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(P/A,g,i,N ) geometric gradient to present worth conversion factor
(P/A,i,N ) series present worth factor
(P/F,i,N ) present worth factor
A annuity amount, equivalent annual cost
A C current dollars in year N
A tot total annuity for arithmetic gradient to annuity conversion factor
A base annuity for arithmetic gradient to annuity conversion factor
AW annual worth
B present worth of benefits
BCR benefit–cost ratio
BCRM modified benefit–cost ratio
BVdb(n) book value at end of period n using declining-balance method
BVsl (n) book value at end of period n using straight-line method
C present worth of costs
CCA capital cost allowance
CSF capital salvage factor
CTF capital tax factor
d depreciation rate for declining-balance method
Ddb(n) depreciation amount for period n using decliningbalance method
Dsl (n) depreciation amount for period n using straight-line method
EAC equivalent annual cost
ERR external rate of return
E(X ) expected value of the random variable, X
F future value, future worth
f inflation rate per year
FW future worth
g growth rate for geometric gradient
i current interest rate
I interest amount
i real interest rate
Ic compound interest amount
ie effective interest rate
is interest rate per subperiod
Is simple interest amount
i° growth adjusted interest rate
IRR internal rate of return
IRRC current dollar IRR
IRRR real dollar IRR
i* internal rate of return
i* e external rate of return
i* ea approximate external rate of return
I0,N the value of a global price index at year N, relative to year 0
m number of subperiods in a period
MARR minimum acceptable rate of return
MARRC current dollar MARR
MARRR real dollar MARR
number of periods, useful life of an asset
present value, present worth, purchase price, principal amount
PW present worth
p(x ) probability distribution
Pr{X = xi} alternative expression of probability distribution
r nominal interest rate, rating for a decision matrix
R0,N real dollar equivalent to AN relative to year 0, the base year
S salvage value
t tax rate
UCC undepreciated capital cost
X random variable
01 Laspeyres price index
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Library and Archives Canada Cataloguing in Publication
Engineering economics : financial decision making for engineers / Niall M. Fraser, Elizabeth M. Jewkes.—5th ed.
First-3rd eds. publ. under title: Engineering economics in Canada. 4th ed. publ. under title: Global engineering economics. Includes bibliographical reference and index.
ISBN 978-0-13-237925-0
1.Engineering economy.I.Fraser, Niall M. (Niall Morris), 1952–II. Jewkes, Elizabeth M. (Elizabeth Marie), 1958-
ISBN 978-0-13-237925-0
BriefContents
Prefacexiii
CHAPTER 1 Engineering Decision Making1
CHAPTER 2 Time Value of Money18
CHAPTER 3 Cash Flow Analysis45
Appendix 3ADerivation of Discrete Compound Interest Factors81
CHAPTER 4 Comparison Methods Part 185
Appendix 4AThe MARR and the Cost of Capital122
CHAPTER 5 Comparison Methods Part 2125
CHAPTER 6 Depreciation and Financial Accounting163
Appendix 6ACost Estimation207
CHAPTER 7 Replacement Decisions215
CHAPTER 8 Taxes263
Appendix 8ADeriving the Capital Tax Factor301
CHAPTER 9 Inflation304
Appendix 9AComputing a Price Index338
CHAPTER 10 Public Sector Decision Making342
CHAPTER 11 Project Management387
CHAPTER 12 Dealing With Uncertainty and Risk424
Appendix 12ADecision Matrices 471
CHAPTER 13 Qualitative Considerations and Multiple Criteria COMPANIONWEBSITE
8.8.2 Undepreciated Capital Cost and the Half-Year Rule 280
8.8.3 The Capital Tax Factor and Capital Salvage Factor 283
8.8.4 Components of a Complete Tax Calculation 285
Review Problems 288
Summary 293
Engineering Economics in Action, Part 8B: The Work Report294
Problems 294
Mini-Case 8.1: Flat Taxes 300
Appendix 8ADeriving the Capital Tax Factor 301
CHAPTER 9 Inflation304
Engineering Economics in Action, Part 9A: The Inflated Expert305
9.1 Introduction 305
9.2 Measuring the Inflation Rate 306
NET VALUE 9.1:STATISTICS CANADA306
9.3 Economic Evaluation With Inflation 308
9.3.1 Converting Between Real and Current Dollars 308
9.4 The Effect of Correctly Anticipated Inflation 311
9.4.1 The Effect of Inflation on the MARR 312
9.4.2 The Effect of Inflation on the IRR 314
9.5 Project Evaluation Methods With Inflation 316
Review Problems 322
Summary 325
Engineering Economics in Action, Part 9B: Exploting Volatility326
Problems 326
Mini-Case 9.1: Economic Comparison of High Pressure and Conventional Pipelines: Associated Engineering 337 Appendix 9AComputing a Price Index 338
CHAPTER 10 Public Sector Decision Making342
Engineering Economics in Action, Part 10A: New Challenges Down Under343
10.1 Introduction 343
10.2 Market Failure 346
10.2.1 Market Failure Defined 346
10.2.2 Remedies for Market Failure 348
10.3 Decision Making in the Public Sector 349
10.3.1 The Point of View Used for Project Evaluation 350 NET VALUE 10.1:CANADIAN BENEFIT–COST ANALYSIS GUIDES352
10.3.2 Identifying and Measuring the Costs of Public Projects 352
10.3.3 Identifying and Measuring the Benefits of Public Projects 353
10.3.4 Benefit–Cost Ratios 356
10.3.5 The MARR in the Public Sector 362
Review Problems 363
Summary 368
Engineering Economics in Action, Part 10B: Look at It Broadly369 Problems 369
Mini-Case 10.1: Emissions Trading 384
CHAPTER 11 Project Management387
Engineering Economics in Action, Part 11A: Filling a Vacuum388
11.1 Introduction 388
11.2 Project Management Lifecycle 389
11.2.1 Initiation 390
11.2.2 Planning 390
11.2.3 Execution 391
11.2.4 Monitoring and Controlling 391
11.2.5 Closure 392
11.3 Project Management Tools 392
11.3.1 Work Breakdown Structure 392
11.3.2 Gantt Charts 394
11.3.3 The Critical Path Method 396
11.3.3.1 Project Scheduling and the Critical Path Method 400
11.3.3.2 Project Crashing and Time–Cost Tradeoffs 403
Review Problems 408
Summary 412
Engineering Economics in Action, Part 11B:A Crash Course412
Problems 413
Mini-Case 11.1: No Longer LEEDing 422
CHAPTER
12 Dealing With Uncertainty and Risk424
Engineering Economics in Action, Part 12A: Trees from Another Planet425
12.1 Introduction 425
12.2 Sensitivity Graphs 426
12.3 Break-Even Analysis 429
12.3.1 Break-Even Analysis for a Single Project 430
12.3.2 Break-Even Analysis for Multiple Projects 432
12.4 Basic Concepts of Probability 436
12.5 Structuring Decisions With Decision Trees 442
NET VALUE 12.1:DECISION TREE SOFTWARE446
Review Problems 448
Summary 454
Engineering Economics in Action, Part 12B: Chances Are Good454
Problems 455
Mini-Case 12.1: China Steel Australia Limited 469 Appendix 12ADecision Matrices 471 Problems 474
Engineering Economics in Action, Part 12C: Moving On476
CHAPTER 13 Qualitative Considerations and Multiple Criteria COMPANIONWEBSITE
Engineering Economics in Action, Part 13A: Don’t Box Them In
13.1 Introduction
13.2 Efficiency
13.3 Decision Matrixes
13.4 The Analytical Hierarchy Process
NET VALUE 13.1: AHP SOFTWARE
13.5 The Consistency Ratio for AHP
Review Problems
Summary
Engineering Economics in Action, Part 13B: Moving On Problems
Mini-Case 13.1: Northwind Stoneware
Appendix A
Compound Interest Factorsfor Discrete Compounding, Discrete Cash Flows477 Appendix B Answers to Selected Problems501
Glossary 507
Photo Credits515 Index 517
Preface
Courses on engineering economics are found in engineering curricula in Canada and throughout the world. The courses generally deal with deciding among alternative engineering projects with respect to expected costs and benefits. The topic is so fundamental to engineering knowledge that the Canadian Engineering Accreditation Board requires that all accredited professional engineering programs provide studies in engineering economics. Many engineers have found that a course in engineering economics can be as useful in their practice as any of their more technical courses.
There are several stages to making a good decision. One stage is being able to determine whether a solution to a problem is technically feasible. This is one of the roles of the engineer, who has specialized training to make such technical judgments. Another stage is deciding which of several technically feasible alternatives is best. Deciding among alternatives often does not require the technical competence needed to determine which alternatives are feasible, but it is equally important in making the final choice. Some engineers have found that choosing among alternatives can be more difficult than deciding what alternatives exist.
The role of engineers in Canadian society has changed. In the past, engineers tended to have a fairly narrow focus, concentrating on the technical aspects of a problem and on strictly computational aspects of engineering economics. As a result, many engineering economics texts focused on the mathematics of the subject. Today, engineers are more likely to be involved in many stages of an engineering project, and thus they need to be able to take into account strategic and policy issues.
This book is designed for teaching a course on engineering economics to match engineering practice in Canada today. It recognizes the role of the engineer as a decision maker who has to make and defend sensible decisions. Such decisions must not only take into account a correct assessment of costs and benefits; they must also reflect an understanding of the environment in which the decisions are made.
This book has had four previous editions. The first three editions were focussed on Engineering Economics from a Canadian perspective. Given the increasing globalization of many engineering activities, the title and content were updated in the fourth edition to reflect that engineers increasingly worked in an international setting. Feedback from our users on the fourth edition has brought the fifth edition back to its original Canadian perspective. This book has been the text of choice for many Canadian educators for over 15 years.
Canadian engineers have a unique set of circumstances that warrant a text with a specific Canadian focus. Canadian firms make decisions according to norms and standards that reflect Canadian views on social responsibility, environmental concerns, and cultural diversity. This perspective is reflected in the content and tone of much of the material in this book. Furthermore, Canadian tax regulations are complicated and directly affect engineering economic analysis. These regulations and their effect on decision making are covered in detail in Chapter 8.
This book also relates to students’ everyday lives. In addition to examples and problems with an engineering focus, there are a number that involve decisions that many students might face, such as renting an apartment, getting a job, or buying a car. Other examples in the text are adapted from familiar sources such as Canadian newspapers and well-known Canadian companies.
Content and Organization
Because the mathematics of finance has not changed dramatically over the past number of years, there is a natural order to the course material. Nevertheless, a modern view of the role of the engineer flavours this entire book and provides a balanced exposure to the subject.
Chapter 1 frames the problem of engineering decision making as one involving many issues. Manipulating the cash flows associated with an engineering project is an important process for which useful mathematical tools exist. These tools form the bulk of the remaining chapters. However, throughout the text, students are kept aware of the fact that the eventual decision depends not only on the cash flows, but also on less easily quantifiable considerations of business policy, social responsibility, and ethics.
Chapters 2 and 3 present tools for manipulating monetary values over time. Chapters 4 and 5 show how students can use their knowledge of manipulating cash flows to make comparisons among alternative engineering projects. Chapter 6 provides an understanding of the environment in which the decisions are made by examining depreciation and the role it plays in the financial functioning of a company and in financial accounting. Because students frequently ask “where do the numbers come from?” we have added in this new edition a brief overview of cost estimating as an appendix to Chapter 6.
Chapter 7 deals with the analysis of replacement decisions. Chapters 8 and 9 are concerned with taxes and inflation, which affect decisions based on cash flows. Chapter 10 provides an introduction to public sector decision making.
Chapter 11, new to this edition, provides an introduction to project management. Engineers should have an appreciation of the phases that all engineering projects pass through, as well as the role engineering economics plays in evaluating the economic feasibility of a project.
Most engineering projects involve estimating future cash flows as well as other project characteristics. Since estimates can be made in error and the future is unknown, it is important for engineers to take uncertainty and risk into account as completely as possible. Chapter 12 addresses several approaches for dealing with uncertainty and risk in economic evaluations.
New to This Edition
In addition to updating material and correcting errors, we have made the following important changes in the fifth edition:
■ We have introduced a Spreadsheet Savvy feature to each chapter. As a running theme, each feature highlights how spreadsheets and, in particular, Excel functionality, can be used to support the student as he or she learns the basic concepts covered in the chapter. The textbook does not provide a tutorial on the general use of spreadsheets; this task is left to others. However, it does highlight spreadsheet features that are relevant to the engineering economic topics contained in each chapter and instructs students on their use.
While many instructors will want to ensure that students are able to conduct the economic analysis from first principles, in practice, students should also know how to make best use of the tools commonly available in the workplace. In addition to the Spreadsheet Savvy features, for selected examples in each chapter, we have noted where Excel spreadsheets can be used to compute the answer to a problem.
■ Chapter 6 now features an appendix on cost estimation. This appendix provides an overview of how cash flows are estimated and how the level of detail contained in the estimation depends on the purpose of the estimation, whether it is for early-stage project assessment or later detailed estimates for use in project monitoring and control.
■ Chapter 8 on taxation has undergone a major revision in order to focus on the Canadian tax system. The current chapter benefits from the fourth edition material in that the information was reorganized around generic themes in taxation. The current chapter includes these generic themes, but now also contains an emphasis on Canadian tax rules.
■ Chapters 11, 12, and 13 from the fourth edition have been combined and shortened into a new Chapter 12 entitled “Dealing with Uncertainty and Risk.” We removed more advanced topics that will likely be covered in other courses and focused on key decision-making topics that will be useful for any instructor who wants to include an introduction to uncertainty and risk in decision making.
■ The text has a completely new Chapter 11 on project management. This chapter responds well to the new Canadian Engineering Accreditation Board (CEAB) accreditation criteria for engineering schools to teach both economics and project management in their curricula. Chapter 11 provides introductory coverage of project management and can be used as the basis for reinforcement and mastery through subsequent course projects, team competitions, and other program components.
■ We reorganized and renumbered the problem sets throughout the text. Each chapterend problem set is divided into three categories: Key Concepts, Applications, and More Challenging Problems. These correspond well with the new CEAB requirement for learning outcome levels of “introduction,” “reinforcement,” and “mastery.”
■ Minor changes to all other chapters have been made to update and improve the overall flow and presentation of the material.
Special Features
We have created special features for this book in order to facilitate the learning of the material and an understanding of its applications:
■ Engineering Economics in Action boxes near the beginning and end of each chapter recount the fictional experiences of a young engineer at a Canadian company. These vignettes reflect and support the chapter material. The first box in each chapter usually portrays one of the characters trying to deal with a practical problem. The second box demonstrates how the character has solved the problem by applying material discussed in the chapter above. All these vignettes are linked to form a narrative that runs throughout the book. The main character is Naomi, a recent engineering graduate. In the first chapter, she starts her job in the engineering department at Canadian Widgets and is given a decision problem by her supervisor. Over the course of the book, Naomi learns about engineering economics on the job. There are several characters, who relate to one another in various ways, exposing students to practical, ethical, and social issues as well as mathematical problems.
ENGINEERING ECONOMIC S IN ACTION, PART U
Naomi Arrives
Naomi's first day on the job wasn't really her first day on the job Ever since slis had received the acceptance letter three weeks earlier, she had been reading and rereading all her notes about the company Somehow she had arranged to walk past the plant entrance going on errandsthat never would have taken her that route in the past So today wasn't the first time she had walked through that tidy brick entrance to the main offices ol Canadian Widgets—she had done It the same way In her imagination a hundred times before
Clement Sheng, the engineering manager who had interviewed Naomi for the job, was waiting for her at the reception desk His warm smile and easy manner did a lot to break the ice He suggested that they could go through the plant on the way to her desk She agreed enthusiast!call/, "I hope you rememberthe engineering economics you learned in school," he said,
Naomi did, but rather than sound like a know-it-all, she replied, "I think so and I still have my old textbook I suppose you're telling meI'm going to use it."
"Yes That's where we'll start you out, anyhow It's a good •;..?; for you to learn how things work around here We've got some projects lined up lor you already, and they involve some pretty big decisions for Canadian Widgets We'll keep you busy."
■ Spreadsheet Savvy boxes in the chapters point out elements of Excel that relate to the chapter material and how Excel can be used to support the computations necessary to implement the concepts covered. From the basics of computing interest rates or the present worth of a series of cash flows to a full-blown analysis of major projects, spreadsheets help engineers compute results, evaluate alternatives, document outcomes, and make recommendations to colleagues and other stake holders.
SPREADSHEE T SAVV Y
A spreadsheet program is a useful way of performing calculations that are more complex than can be easily handled using a calculator.In particular, a spreadsheet program allows you to organize data into a grid and perform simultaneous calculations on rows, columns, or other subsets of the data Spreadsheet programs are used extensively by engineers and are particularly helpful for engineering economics calculations. In this book, we will focus on the popular Microsoft Excel, but other spreadsheet programs have similar functionality
A sample Excel spreadsheet is shown below Each cell in the spreadsheet contains either a value (such as a number or text) or a formula. Text was entered into cells Al and A2 to label rows 1 and 2. Then the integers 1 through 5 were entered into cells B2 through F2, Row 2 computes the cumulative sum of the values in row 1 The summation starts by entering "=B1" in cell B2 Proceeding to the right, cell C2 is the sum of B2 and Cl, cell D2 is the sum of C2 and Dl, and so forth
In normal use of a spreadsheet, the calculation result (as shown in row 2) appears by default If you wish to display the formulas in a spreadsheet, click on the Formulas tab and select ShowFormulas The forumlas for the above spreadsheet are asfollows:
To return to the default display, go back to the Formulas tab and click on Show Formulas again
■ Close-Up boxes in the chapters present additional material about concepts that are important but not essential to the chapter.
CLOSE-UP 2.1
Interest Periods
The most commonly used interest period is one year If we say, for example, "6 percent interest" without specifying an interest period, me assumption is that 6 percent interest is paid for a one-year period However, interest periods can be of any duration Here are some other common interest periods:
■ In each chapter, a Net Value box provides a chapter-specific example of how the internet can be used as a source of information and guidance for decision making.
Professional Engineering Associations
Each of the provincial engineering associations has a website that can be a good source of information about engineering practice. At time of publication, the engineering association websites are:
A1111:na: www apegga.com
British Columbia: www.apeg.bc.ca
Engineers Canada: www.engineerscanada.ca
Manitoba: www.apcgin.mb.ca
New Brunswick: www.apegnb.ca
Newfoundland and Labrador: www.pegnl.ca
North West Territories & Nunavut: www napegg nt ca
Nova Scotia: www.engineersnovascotia.ca
Ontario: www.peo.on.ca
Prince Edward Island: www.engineerspei.com
Quebec: www.oiq.qc.ca
Saskatchewan: www.apegs.sk.ca
These sites contain information such as recent salary surveys, the regional code of ethics along with disciplinary actions, job advertisements, member's director}', news releases and other useful information about the practice of engineering across Canada.
Engineers Canada is a National organization of the provincial and territorial and associations that regulate the profession of engineering in Canada Their site contains information about the programs and services that Engineers Canada supports
The Canadian Engineering Accreditation Board (CEAB), established by Engineers Canada, accredits undergraduate engineering programs to ensure they provide the academic requirements needed for becoming a licensed professional engineer in Canada
■ At the end of each chapter, a Canadian Mini-Case, complete with discussion questions, relates interesting stories about how familiar Canadian companies have used engineering economic principles in practice.
MINI-CAS E 4. 1
Rockwell International
Tliu I.is;ln \'chide Division of Rotkwdl Imtrrmion;)! nwkus sen-slide iissemlilics for dig automotive industry It hastwo major classifications for investment opportunities: developing new products to lie manufactured and sold, and developing new machines to improve production The overall approach to assessing whether an investment should be made depends on die nature of the project
In evaluating a new product, it considers the following:
1 Marketing strategy: Does it fit the businessplan for the company?
2 Work fine: How will it affect human resources?
3 Margins: The product should generate appropriate profits
4 Cashflow. Positive cash flow is expected within two years
In evaluating a new machine, it considers the following;
1, Cashflow: Positive cash flow is expected within a limited time period,
2 Quality issues: For issues of quality, justification is based on cost avoidance rather than positive cash flow
3- Cost avoidance: Savings should pay hack an investment within one year
Additional Pedagogical Features
■ Each chapter begins with a list of the major sections to provide an overview of the material that follows.
■ Key terms are boldfaced where they are defined in the body of the text. For easy reference, all these terms are defined in a glossary near the back of the book.
■ Additional material is presented in chapter appendices at the ends of Chapters 3, 4, 6, 8, 9, and 12.
■ Numerous worked-out Examples are given throughout the chapters. Although the decisions have often been simplified for clarity, most of them are based on real situations encountered in the authors’ consulting experiences.
■ Worked-out Review Problems near the end of each chapter provide more complex examples that integrate the chapter material.
■ A concise prose Summary is given for each chapter.
■ Each chapter has 30 to 50 Problems of various levels of difficulty covering all of the material presented. Like the worked-out Examples, many of the problems have been adapted from real situations.
■ A spreadsheet icon indicates where examples involve the use of spreadsheets, which are available on the Instructor’s Resource Centre.
■ Tables of Interest Factors are provided in Appendix A
■ Answers to Selected Problems are provided in Appendix B.
■ For convenience, a List of Symbols used in the book is given on the inside of the front cover, and a List of Formulas is given on the inside of the back cover.
Course Designs
This book is ideal for a one-term course, but with supplemental material it can also be used for a two-term course. It is intended to meet the needs of students in all engineering programs, including, but not limited to, aeronautical, chemical, computer, electrical, industrial, mechanical, mining, and systems engineering. Certain programs emphasizing public projects may wish to supplement Chapter 10, “Public Sector Decision Making,” with additional material.
A course based on this book can be taught in the first, second, third, or fourth year of an engineering program. The book is also suitable for college technology programs. No more than high school mathematics is required for a course based on this text. The probability theory required to understand and apply the tools of uncertainty and risk analysis is provided in Chapter 12. Prior knowledge of calculus or linear algebra is not needed. This book is also suitable for self-study by a practitioner or anybody interested in the economic aspects of decision making. It is easy to read and self-contained, with many clear examples. It can serve as a permanent resource for practising engineers or anyone involved in decision making.
Supplements
For Students
Companion Website (www.pearsoncanada.ca/fraser) : We have created a robust, password-protected Companion Website to accompany the book. It contains the following items for students and instructors:
■ Practice Quizzes for each chapter. Students can try these self-test questions, send their answers to an electronic grader, and receive instant feedback. These quizzes were revised for the fifth edition by Claude Théoret at the University of Ottawa.
■ Additional Challenging Problems with selected solutions. These problems created by John Jones at Simon Fraser University, were provided on the CD-ROM in the previous edition.
■ Excel spreadsheets for selected Spreadsheet Savvy discussions, examples (designated by a spreadsheet icon in the book), and problems.
■ Chapter 13, “Qualitative Considerations and Multiple Criteria” from our Fraser et al., Global Engineering Economics: Financial Decision Making for Engineers Fourth Edition.
■ Extended Cases
■ Interest Tables:
■ Compound Interest Factors for Continuous Compounding, Discrete Cash Flows
■ Compound Interest Factors for Continuous Compounding, Continuous Compounding Periods
■ Glossary Flashcards
■ Pearson eText. Pearson eText gives students access to the text whenever and wherever they have access to the Internet. eText pages look exactly like the printed text, offering powerful new functionality for students and instructors. Users can create notes, highlight text in different colours, create bookmarks, zoom, click hyperlinked words and phrases to view definitions, and view in single-page or two-page view. Pearson eText allows for quick navigation to key parts of the eText using a table of contents and provides full-text search.
For Instructors
The following instructor supplements are available for downloading from a passwordprotected section of Pearson Canada’s online catalogue (www.pearsoncanada.ca/highered). Navigate to your book’s catalogue page to view a list of those supplements that are available. See your local sales representative for details and access.
Instructor’s Solutions Manual. The Solutions Manual contains full solutions to all the problems in the book, full solutions to all the additional problems, model solutions to the extended cases on the Companion Website, teaching notes for the MiniCases, and Excel spreadsheets for selected examples and problems. This manual was created by the text authors.
Computerized Testbank (Pearson TestGen). This bank allows instructors to view and edit all questions, generate tests, print tests in a variety of formats, administer tests on a local area network, and have the tests graded electronically. The questions were revised for the fifth edition by Yuri Yevdokimov at the University of New Brunswick, Fredericton.
Image Library. We have compiled all of the figures and tables from the book in electronic format.
CourseSmart for Instructors. CourseSmart goes beyond traditional expectations— providing instant, online access to the textbooks and course materials you need at a lower cost for students. And even as students save money, you can save time and hassle with a digital eTextbook that allows you to search for the most relevant content at the very moment you need it. Whether it’s evaluating textbooks or creating lecture notes to help students with difficult concepts, CourseSmart can make life a little easier. See how when you visit www.coursesmart.com/instructors.
Technology Specialists. Pearson’s Technology Specialists work with faculty and campus course designers to ensure that Pearson technology products, assessment tools, and online course materials are tailored to meet your specific needs. This highly qualified team is dedicated to helping schools take full advantage of a wide range of educational resources, by assisting in the integration of a variety of instructional materials and media formats. Your local Pearson Education sales representative can provide you with more details on this service program.
Pearson Custom Library. For enrollments of at least 25 students, you can create your own textbook by choosing the chapters that best suit your own course needs. To begin building your custom text, visit www.pearsoncustomlibrary.com. You may also work with a dedicated Pearson Custom editor to create your ideal text—publishing your own original content or mixing and matching Pearson content. Contact your local Pearson Representative to get started.
Acknowledgments
The authors wish to acknowledge the contributions of a number of individuals who assisted in the development of this text. First and foremost are the hundreds of engineering students at the University of Waterloo who have provided us with feedback on passages they found hard to understand, typographical errors, and examples that they thought could be improved. There are too many individuals to name in person, but we are very thankful to each of them for their patience and diligence.
Other individuals who have contributed strongly to previous editions of the book include Irwin Bernhardt, May Tajima, Peter Chapman, David Fuller, J.B. Moore, Tim Nye, Ron Pelot, Victor Waese, Yuri Yevdokimov, and Peggy Fraser.
During the development process for the new edition, Pearson Canada arranged for the anonymous review of parts of the manuscript by a number of very able reviewers. These reviews were extremely beneficial to us, and many of the best ideas incorporated in the final text originated with these reviewers. We can now thank them by name:
James S. ChristieUniversity of New Brunswick, Saint John Raad JassimMcGill University
John JonesSimon Fraser University
Muslim A. MajeedCarleton University
Prashant MhaskarMcMaster University
Juan PerniaLakehead University
Claude ThéoretUniversity of Ottawa
Frank TrimnellRyerson University
Yuri YevdokimovUniversity of New Brunswick, Fredericton
Finally, we want to express our appreciation to the various editors at Pearson Canada for their professionalism and support during the writing of this book. Our developmental editors for most this edition, Rema Celio and Eleanor MacKay, were able support for the author team. Our very capable and expert production and design team included: Ioana Gagea, Lesley Deugo, Ridhi Mathur, Sally Glover, and Anthony Leung. We remain grateful to Maurice Esses, who played a particularly strong role in bringing the first and second editions to completion; his guidance was instrumental in making it possible for this edition to exist. Finally, we would like to recognize Paul McInnis, the Pearson Education sales representative for this text, for his initial encouragement to write this book and his continued support and feedback over the past 15 years.
To all of the above, thank you again for your help. To those we may have forgotten to thank, our appreciation is just as great, even if our memories fail us. Without doubt, some errors remain in this text in spite of the best efforts of everyone involved. To help us improve for the next edition, if you see an error, please let us know.
Niall M. Fraser
Elizabeth M. Jewkes
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Engineering Decision Making
Engineering Economics in Action, Part 1A: Naomi Arrives
1.1 Engineering Decision Making
1.2 What Is Engineering Economics?
1.3 Making Decisions
Engineering Economics in Action, Part 1B: Naomi Settles In
1.4 Dealing With Abstractions
1.5 The Moral Question: Three True Stories
1.6 Uncertainty and Sensitivity Analysis
1.7 How This Book Is Organized
Engineering Economics in Action, Part 1C: A Taste of What Is to Come
Problems
Mini-Case 1.1: R. v. Syncrude Canada Ltd.
ENGINEERING ECONOMICS IN ACTION, PART 1A
Naomi Arrives
Naomi’s first day on the job wasn’t really her first day on the job. Ever since she had received the acceptance letter three weeks earlier, she had been reading and rereading all her notes about the company. Somehow she had arranged to walk past the plant entrance going on errands that never would have taken her that route in the past. So today wasn’t the first time she had walked through that tidy brick entrance to the main offices of Canadian Widgets—she had done it the same way in her imagination a hundred times before.
Clement Sheng, the engineering manager who had interviewed Naomi for the job, was waiting for her at the reception desk. His warm smile and easy manner did a lot to break the ice. He suggested that they could go through the plant on the way to her desk. She agreed enthusiastically. “I hope you remember the engineering economics you learned in school,” he said.
Naomi did, but rather than sound like a know-it-all, she replied, “I think so, and I still have my old textbook. I suppose you’re telling me I’m going to use it.”
“Yes. That’s where we’ll start you out, anyhow. It’s a good way for you to learn how things work around here. We’ve got some projects lined up for you already, and they involve some pretty big decisions for Canadian Widgets. We’ll keep you busy.”
1.1 Engineering Decision Making
Engineering is a noble profession with a long history. The first engineers supported the military using practical know-how to build bridges, fortifications, and assault equipment. In fact, the term civil engineer was coined to make the distinction between engineers who worked on civilian projects and engineers who worked on military problems.
In the beginning, all engineers had to know were the technical aspects of their jobs. Military commanders, for example, would have wanted a strong bridge built quickly. The engineer would be challenged to find a solution to the technical problem, and would not have been particularly concerned about the costs, safety, or environmental impacts of the project. As years went by, however, the engineer’s job became far more complicated.
All engineering projects use resources, such as raw materials, money, labour, and time. Any particular project can be undertaken in a variety of ways, with each one calling for a different mix of resources. For example, an incandescent light bulb requires inexpensive raw materials and little labour, but it is inefficient in its use of electricity and doesnot last very long. On the other hand, a high-efficiency light bulb uses more expensive raw materials and is more expensive to manufacture, but consumes less electricity and lasts longer. Both products provide light, but choosing which is better in a particular situation depends on how the costs and benefits are compared.
Historically, as the kinds of projects engineers worked on evolved and technology provided more than one way of solving technical problems, engineers were more often faced with having to choose among alternative solutions to a problem. If two solutions both dealt with a problem effectively, clearly the less expensive one was preferred. The practical science of engineering economics was originally developed specifically to deal with determining which of several alternatives was, in fact, the most economical.
Choosing the least expensive alternative, though, is not the entire story. Though a project might be technically feasible and the most reasonably priced solution to a problem, if the money isn’t available to do it, it can’t be done. The engineer has to become aware of the financial constraints on the problem, particularly if resources are very limited. In addition, an engineering projectcan meet all other criteria, but may cause detrimental environmental effects. Finally, any project can be affected by social and political constraints. For example, a large irrigation project called the Garrison Diversion Unit in North Dakota was effectively cancelled because of political action by Canadians and environmental groups, even though over $2000000000 had been spent.
Engineers today must make decisions in an extremely complex environment. The heart of an engineer’s skill set is still technical competence in a particular field. This permits the determination of possible solutions to a problem. However, necessary to all engineering is the ability to choose among several technically feasible solutions and to defend that choice credibly. The skills permitting the selection of a good choice are common to all engineers and, for the most part, are independent of which engineering field is involved. These skills form the discipline of engineering economics.
1.2 What Is Engineering Economics?
Just as the role of the engineer in society has changed over the years, so has the nature of engineering economics. Originally, engineering economics was the body of knowledge that allowed the engineer to determine which of several alternatives was economically best—the least expensive, or perhaps the most profitable. In order to make this determination properly, the engineerneeded to understand the mathematics governing the relationship between time and money. Most of this book deals with teaching and using this knowledge. Also, for many kinds of decisions, the costs and benefits are the most important factors affecting the decision, so concentrating on determining the economically “best” alternative is appropriate.
In earlier times, an engineer would be responsible for making a recommendation on the basis of technical and analytic knowledge, including the knowledge of engineering economics, and then a manager would decide what should be done. A manager’s decision could be different from the engineer’s recommendation because the manager would take into account issues outside the engineer’s range of expertise. Recently, however, the trend has been for managers tobecome more reliant on the technical skills of the engineers, or for the engineers themselves to be the managers. Products are often very complex, manufacturing processes are fine-tuned to optimize productivity, and even understanding the market sometimes requires the analytic skills of an engineer. As a result, it is often only the engineer who has sufficient depth of knowledge to make a competent decision.
Consequently, understanding how to compare costs, although still of vital importance, is not the only skill needed to make suitable engineering decisions. One must also be able to take into account all the other considerations that affect a decision, and to do so in a reasonable and defensible manner.
Engineering economics, then, can be defined as the science that deals with techniques of quantitative analysis useful for selecting a preferable alternative from several technically viable ones.
The evaluation of costs and benefits is very important, and it has formed the primary content of engineering economics in the past. The mathematics for doing this evaluation, which is well developed, still makes up the bulk of studies of engineering economics.
However, the modern engineer must be able to recognize the limits and applicability of these economic calculations and must be able to take into account the inherent complexity of the real world.
1.3 Making Decisions
All decisions, except perhaps the most routine and automatic ones or those that are institutionalized in large organizations, are made, in the end, on the basis of belief as opposed to logic. People, even highly trained engineers, do what feels like the right thing to do. This is not to suggest that one should trust only one’s intuition and not one’s intellect, but rather to point out something true about human nature and the function of engineering economics studies.
Figure 1.1 is a useful illustration of how decisions are made. At the top of the pyramid are preferences, which directly control the choices made. Preferences are the beliefs about what is best, and are often hard to explain coherently. They sometimes have an emotional basis and include criteria and issues that are difficult to verbalize.
The next tier is composed of politics and people. Politics in this context means the use of power (intentional or not) in organizations. For example, if the owner of a factory has a strong opinion that automation is important, this has a great effect on engineering decisions on the plant floor. Similarly, aninfluential personality can affect decision making. It’s difficult to make a decision without the support, either real or imagined, of other people. This support can be manipulated, for example, by a persuasive salesperson or a persistent lobbyist. Support might just be a general understanding communicated through subtle messages.
The next tier is a collection of facts. The facts, which may or may not be valid or verifiable, contribute to the politics and the people, and indirectly to the preferences. At the bottom of the pyramid are the activities that contribute to the facts. These include a
Figure 1.1Decision Pyramid
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AGORÁCRITO.
Pero no te aflijas; no es tuya la culpa, sino de los que te engañaron Ahora contéstame: si algún abogado chocarrero te dice: «Jueces, no tendréis pan si no condenáis a este acusado», ¿qué le harás?
PUEBLO.
Lo levantaré en alto y lo arrojaré al Báratro[433] , colgándole del cuello a Hipérbolo.
AGORÁCRITO.
¡Hola!, en esto ya andas acertado y discreto. Pero, y los otros asuntos de la república ¿cómo los arreglarás?
PUEBLO.
En cuanto lleguen al puerto los remeros de los navíos de guerra les pagaré íntegro su sueldo[434]
AGORÁCRITO.
Providencia grata a muchas asendereadas posaderas.
PUEBLO.
Después mandaré que ningún ciudadano inscrito en la lista de los hoplitas[435] pueda pasar por recomendación a otro orden; cada cua estará en la lista donde se le apuntó al principio.
AGORÁCRITO.
Eso va derecho contra el escudo de Cleónimo[436] .
PUEBLO.
Ningún imberbe podrá hablar en la asamblea.
AGORÁCRITO.
¿Y dónde perorarán Clístenes y Estratón?[437]
PUEBLO.
Hablo de esos jovenzuelos que frecuentan las tiendas de perfumes donde charlan así: «¡Qué docto es Féax![438] ¡Cuán acertada ha sido su educación! Se apodera del ánimo de sus oyentes y los conduce a su fin: es sentencioso, sabio, y muy diestro en mover las pasiones y en dominar un tumulto.»
AGORÁCRITO.
¿Acaso estás apasionado de esos charlatanes?
PUEBLO.
No, por cierto; a todos les obligaré a irse de caza, en vez de hace decretos.
AGORÁCRITO.
Con esa condición, toma esta silla, y este robusto muchacho para que la lleve; si te agrada, puedes sentarte sobre él[439] .
PUEBLO.
¡Qué felicidad recobrar mi antiguo estado!
AGORÁCRITO.
Eso lo podrás decir cuando te entregue las treguas por treinta años ¡Hola, Treguas[440], presentaos pronto!
PUEBLO.
¡Júpiter supremo! ¡Qué hermosas son! Dime, por los dioses: ¿puede tratarse con ellas? ¿Dónde las encontraste?
AGORÁCRITO.
Pues qué, ¿no las tenía guardadas el Paflagonio para que tú no las hallases? Yo te las doy; vete al campo y llévatelas.
PUEBLO.
¿Qué castigo vas a imponer a ese Paflagonio que ha hecho tanto mal?
AGORÁCRITO.
Uno pequeño. No le impondré más que el de ejercer mi antiguo oficio: vender chorizos en las puertas, y picar carnes de perros y burros[441] . Cuando se embriague, reñirá con las prostitutas, y no beberá más agua que la de las bañeras.
PUEBLO.
Excelente idea: nadie más digno que él de destrozarse a denuestos con los bañeros y prostitutas. En recompensa de tantos beneficios te invito a venir al Pritaneo y a ocupar en él la silla de aquel miserable
Sígueme y coge esa túnica verde-rana. Conducid al Paflagonio al sitio donde ha de ejercer su oficio, para que lo vean los extranjeros a quienes solía ultrajar.
.
LAS NUBES.
NOTICIA PRELIMINAR.
«El año último dirigió el poeta sus ataques contra esos vampiros que, pálidos abrasados por incesante fiebre, estrangulaban en las tinieblas a vuestros padres y abuelos, y acostados en el lecho de los ciudadanos pacíficos, enemigos de cuestiones, amontonaban sobre ellos procesos, citaciones y testigos, hasta el punto de que muchos acudieron aterrados al polemarca. Y esto no obstante, el año pasado abandonasteis al intrépido defensor que puso todo su ahínco en purgar de tales monstruos a la patria, precisamente cuando sembraba pensamientos de encantadora novedad, cuyo crecimiento impedisteis por no haberlos comprendido bien. Sin embargo, el autor jura a menudo, entre estas libaciones a Baco, que jamás oísteis mejores versos cómicos. Vergonzoso es que no comprendieseis de seguida su intención profunda; pero al poeta le consuela el no haber desmerecido en la opinión de los doctos, aunque se hayan estrellado sus esperanzas por vencer en audacia a sus rivales.»
Así explica Aristófanes, en la Parábasis de Las Avispas, el objeto de Las Nubes, y el elevado concepto que tenía formado de esta comedia una de las más hermosas creaciones de su fantasía. Las Nubes son en efecto, una sátira ingeniosa y trascendental de los vicios que en la educación iban introduciéndose merced, especialmente, a la influencia de los sofistas, ídolos entonces de la juventud, que frecuentaba solícita sus escuelas. Los sofistas habían aparecido en Atenas en tiempo de Pericles, y, abusando de la invención de Zenón el eleático, esgrimieron las armas de la dialéctica para satisfacer sus miras interesadas y ambiciosas. En sus discursos, exornados con todas las galas de la oratoria, no se proponían como objeto principal la demostración científica de un sistema de verdades, sino el deslumbrar a sus oyentes, sosteniendo, con aquellos falaces argumentos que de ellos
han recibido el nombre de sofismas, las más absurdas conclusiones y extrañas paradojas.
Ensoberbecidos con su ingenio, disputaban atrevidamente de omn re scibili, y sostenían indistintamente el pro y el contra en todas las cuestiones, llegando, por este funesto modo de filosofar, a convertir la varonil elocuencia antigua en un arte de disputar artificiosamente, a llevar las inteligencias al escepticismo y a la negación de los dioses, y a relajar los más fuertes vínculos sociales con la predicación de una moral cuyo único móvil era el carpe diem y el placer. «El talento de hacer justo lo injusto, e injusto lo justo, que orgullosamente se atribuían, debía de ser, dice Schœll, siguiendo a Heeren[442] extremadamente peligroso en sus relaciones con la vida civil; pero aún producía un mal mayor, cual es el de echar por tierra el sentimiento de la verdad, que deja de ser respetable desde el momento en que se la considera discutible.»
Aristófanes, que siempre estaba con el látigo levantado contra todo abuso y todo error, lo descargó también sobre estos maestros ateos vanos e inmorales, impulsado por el noble, levantado y patriótico pensamiento de restaurar aquel sistema de enseñanza que formó los héroes de Maratón e hizo reinar en las costumbres la modestia y la virtud; pero al hacerlo cometió la imperdonable falta de elegir como blanco de sus tiros y personificación de los sofistas la venerable figura de Sócrates, que era precisamente el más declarado de sus enemigos
¿Qué motivo pudo impulsar a Aristófanes a semejante elección y a acumular sobre la cabeza del virtuoso filósofo los anatemas con que quiere confundir la nueva educación? ¿Por qué acusar de corruptor de la juventud al que solo pretendía dirigirla al bien, de ateísmo al hombre más piadoso, de avaricia al más generoso y desprendido, y de perderse en nebulosas especulaciones al que sentaba toda su filosofía sobre la base práctica de la moral? Digámoslo en dos palabras: por la misma popularidad de Sócrates y su especial manera de enseñar Sócrates, que no explicaba dentro del recinto de una escuela, sino en los lugares más concurridos; que empleaba todos los recursos de su natural gracejo en la disputa y en la exposición de sus doctrinas, era indudablemente el filósofo más conocido de los atenienses, y sin duda por eso lo eligió Aristófanes para personificar en él toda la filosofía de su tiempo, obedeciendo a la necesidad de dar unidad a su comedia y de no convertirla en una polémica insípida o pedante.
Es preciso, además, tener en cuenta que Sócrates, como todos los genios, quizá no lo apareciera ante los ojos de sus contemporáneos hasta que su muerte depuró en él, por decirlo así, toda aquella especie de imperfección que empequeñece, cuando se las mira de cerca, las más grandes figuras. Desde luego, aun los más furiosos detractores de Aristófanes no podrán menos de confesar que había motivo para engañarse al apreciar las miras del mártir de la cicuta, cuando se le veía discutir con chistes y cuentecillos entre la plebe menos ilustrada o dar consejos de arte amandi a la bella cortesana Teodota.
Esta singular conducta, cuando sus altos fines no eran bien conocidos, se prestaba indudablemente al ridículo; y por eso Sócrates que despreciaba las vulgares preocupaciones que acerca de é existían, fue el blanco, como dice Séneca, de las envenenadas burlas de los cómicos. Porque no fue solo Aristófanes quien le escarneció en el teatro; Éupolis y Amipsias le llamaron vanidoso, mendigo y ladrón, y es de creer que también otros, dada la declarada guerra que entre poetas cómicos y filósofos y trágicos existía.
No pretendemos con esto, justificar a Aristófanes, sino hace constar que, al componer Las Nubes, aparte de lo indisculpable de la sátira personal y calumniosa, procedió de buena fe, aunque con criminal ligereza, por haber confundido a Sócrates con la turba de sofistas cuya peligrosa enseñanza quería desterrar.
De todos modos, sus insultos no hallaron eco, por esta vez, en e público de Atenas, que, acostumbrado a la extremada licencia de los cómicos, tomaba a risa sus ultrajes y calumnias, o los consideraba como grandes exageraciones. Pues solo así se comprende que aplaudiese a un mismo tiempo los ataques de Aristófanes a Eurípides y su sistema dramático, y las tragedias del inspirado poeta. Sócrates según irrecusables testimonios, continuó después de representadas
Las Nubes siendo querido y respetado, y no pareció guarda resentimiento alguno contra su calumniador. Platón y Jenofonte, sus más afectos discípulos, tampoco tienen para él ni una palabra de censura: al contrario, el primero compuso en su honor un lisonjero dístico y le presentó en el Banquete, conversando amigablemente con el maestro sobre las interesantes teorías del arte, la belleza y el amor
En vista de estos elocuentes hechos y de haber trascurrido nada menos que veinticuatro años entre la primera representación de Las Nubes y la muerte de Sócrates, ha caído ya en descrédito la opinión
de que la comedia aristofánica fue la causa principal de la injusta condena del filósofo. Verdad es que sus enemigos presentaron contra él las mismas acusaciones que en Las Nubes se le hacen; pero también es cierto que no pasaron de ser pretextos especiosos acogidos por un tribunal decidido a condenar a muerte al que había osado censurar la tiranía de los Treinta, y los atropellos de Nicias[443] .
Quitado de Las Nubes el nombre de Sócrates, queda esta comedia como una de las más perfectas de Aristófanes. Muy lisonjeros juicios se han formulado sobre ella; pero como entre los más acertados figura el que mi particular amigo D. Fermín Herrán tuvo la bondad de pone al frente de mi versión en el año 1875, lo inserto a continuación aprovechando esta oportunidad de agradecerle los amables o inmerecidos elogios de que entonces me colmó.
«El argumento de Las Nubes es sencillísimo; parécese en esto a algunos de nuestros autos sacramentales en que la acción se desenvuelve sin tropiezo, sin incidentes que la compliquen, n episodios que la armonicen; ligera, sencilla y fácilmente comprensible.
»Estrepsiades, personaje que Aristófanes nos presenta como la personificación del fraude, tipo que excita la repugnancia, sin dejar de interesar por eso, es un hombre que agobiado de deudas y no teniendo con qué pagarlas, discurre los medios de burlar a sus acreedores dejando a salvo su responsabilidad única cosa que le atemoriza, no por la nota que sobre él podrá echar, sino por la materialidad del pago a que se vería obligado Y en vez de recurrir a la economía, disminuyendo sus gastos deshaciéndose de lo superfluo, o arbitrando recursos de cualquiera manera, cree haber resuelto la cuestión enviando a su hijo Fidípides a la escuela de Sócrates, donde debía aprender a convencer con su elocuencia a los más reacios de sus acreedores, logrando de este modo, y en caso de ser citado a juicio, ganar el pleito obteniendo sentencia favorable, para lo cua había de llevar prevenidos dos discursos, uno justo y otro injusto Pero, en un principio, su hijo Fidípides, que está muy lejos de se un modelo de respeto y cariño filial, se niega a ir a la escuela pretextando la antipatía que siente por aquellos sabios, viéndose Estrepsiades obligado a presentarse él mismo en la escuela
donde es admitido, empezando a recibir las lecciones de Sócrates, que renuncia a sacar partido de un discípulo tan estúpido y desmemoriado que solo recuerda de lo que le enseñan aquello que tiene relación con la manía que le ocupa Viendo que por sí mismo nada consigue, logra, si no convencer persuadir a su hijo a entrar en la escuela, de donde sale con los conocimientos que deseaba, los cuales emplea, no en salvar a su padre de los rigores de una sentencia inminente, sino en cohonestar con argucias o sofismas su conducta depravada; lo que obliga a Estrepsiades a renegar del talento de su hijo y maldecir la hora en que abrigó la idea de que lo adquiriese Ansiando tomar venganza de los autores de su mal, quema la casa de Sócrates, y termina la comedia.
»Como se ve, la acción marcha por sí sola, sin que nada la detenga ni precipite; y la moral, aunque un poco tergiversada, es clara y provechosa, y pudiera condensarse en estas palabras “del mal no puede venir el bien”.
»Por el argumento no podría llamarse a Aristófanes notable dramático, toda vez que el ingenio más mediano es capaz de concebir un asunto tan sencillo; pero hay circunstancias que le avaloran y engrandecen, poniendo a su autor en elevado lugar.
»El diálogo, siempre vivo y animado, se hace notable e interesa por la oportunidad de las réplicas y agudeza de las observaciones. La sátira punzante que encierra, las transparentes alusiones que pone en boca de sus personajes le recomiendan y enaltecen, y los chistes en que abunda hacen la acción amena e interesante, en sumo grado: la intervención de coro podría hacerla pesada y algo monótona, pero es necesaria toda vez que el comentario puesto en su boca hace las veces de moraleja, ilustración del texto y explicaciones de los pasajes además de que, dadas las costumbres de entonces en aque país, no podía prescindirse de él.
»Cuanto de ridículo tienen algunos personajes de la comedia está sacado a luz con tanta gracia, con tal oportunidad, que a pesar de reconocer muchas veces la injusticia y encono de los tiros, se aplaude la puntería en gracia del chiste.
»En los episodios, en ciertas escenas, en determinadas situaciones, luce esplendorosa la habilidad del autor de Las
Nubes. El diálogo entre lo Justo y lo Injusto es admirable y verdadera obra maestra de ática ironía. El poner en boca del hijo niño mimado e insolente, los sofismas que para defender lo contrario, o al menos lo distinto, ha expuesto el padre, bonachón y débil, es de éxito grande y efecto oportuno, como lo es la famosa escena entre el viejo y el filósofo, cuya irónica gracia cuya petulancia e intención son muy superiores a todo encarecimiento.
»Sintetizando: argumento sencillo, lenguaje selecto, diálogos chispeantes y animados, caracteres bien dibujados y correctos episodios divertidos o interesantes.»
La representación de Las Nubes tuvo lugar, según la opinión más probable, el año primero de la Olimpiada ochenta y nueve, o sea e 424 a. J. C. El mismo Aristófanes lo indica al lamentarse de su ma éxito en la parábasis de Las Avispas, representadas el 423, y al habla en aquella comedia de Cleón, como si viviese todavía, siendo así que el célebre demagogo murió en el año décimo de la guerra de Peloponeso, que corresponde al segundo de la Olimpiada ochenta y nueve.
PERSONAJES.
E .
F .
U E .
D S
S .
C N
E R .
E R .
P , acreedor.
U P .
A , acreedor.
Q .
LAS NUBES.
La escena representa el dormitorio de Estrepsiades. Este aparece en su lecho, y próximos a él duermen su hijo, y los esclavos.
ESTREPSIADES.
¡Oh Júpiter supremo! ¿Es acaso interminable la duración de las noches? ¿Nunca se hará de día? Mucho tiempo ha que he oído e canto del gallo, y sin embargo, los esclavos aún están roncando: antes no sucedía esto. Maldita sea la guerra, que me impide hasta e castigar a mis esclavos[444] Este buen mozo no despierta en toda la noche, y duerme profundamente[445] , envuelto en las cinco mantas de su lecho. Pero probemos a imitarle...
¡Pobre de mí! no puedo conciliar el sueño. ¿Cómo he de dormir, s me atormentan los gastos, la caballeriza y las deudas que he contraído por causa de este hijo? Él cuida su cabellera, cabalga, guía un carro y sueña con caballos; y yo me siento morir cuando llega el día veinte del mes, porque se acerca el momento de pagar los intereses...[446] .
Muchacho, enciende la lámpara y tráeme el libro de cuentas, para que examine los gastos, y averiguando a quiénes debo, calcule los intereses... Ea, veamos, ¿cuánto debo? «Doce minas a Pasias[447]» ¿Y por qué doce minas a Pasias? ¿En qué las he gastado? Cuando compré el Coppatia[448] ¡Desdichado de mí! ¡Ojalá me hubiesen vaciado antes un ojo de una pedrada![449] .
FIDÍPIDES (soñando).
Filón, guías mal: tu carro debe seguir a este.
ESTREPSIADES.
He aquí el mal que me mata: hasta durmiendo sueña con caballos.
FIDÍPIDES (soñando).
¿Cuántas carreras es necesario dar en el certamen?
ESTREPSIADES.
A tu padre sí que le haces dar carreras... ¿Pero qué deuda contraje[450] después de la de Pasias? Veamos: «tres minas a Aminias[451] por el carro y las ruedas.»
FIDÍPIDES (soñando).
Lleva el caballo a la cuadra y revuélcalo antes en la arena.
ESTREPSIADES.
¡Infeliz! Tú si que das vuelco a mi fortuna; unos me tienen ya citado a los tribunales, otros me piden que les garantice el pago de los intereses[452] .
FIDÍPIDES (despertando).
Pero, padre, ¿qué te angustia que no haces más que dar vueltas toda la noche?
ESTREPSIADES.
Me muerde cierto demarco[453] de las camas.
FIDÍPIDES.
Por favor, querido, déjame dormir un poco.
ESTREPSIADES.
Duerme en hora buena, pero sabe que todas estas deudas caerán sobre tu cabeza... ¡Oh! ¡Así perezca miserablemente aquella casamentera que me impulsó a contraer matrimonio con tu madre Porque yo tenía una vida dulcísima, sencilla, grosera, descuidada y abundante en panales, ovejas y aceite. Después, aunque era hombre del campo, me casé con la nieta de Megacles hijo de Megacles ciudadana soberbia, amiga de los placeres, con las mismas costumbres que Cesira[454] . Después del matrimonio, cuando nos acostábamos, yo no olía más que a mosto, higos y lana de mis ovejas ella por el contrario, apestaba a pomadas y esencias, y solo deseaba besos amorosos, lujo, comilonas y los placeres de Venus[455] . No diré que fuese holgazana, sino que tejía; y muchas veces, enseñándola
esta capa, le decía con tal pretexto: «Esposa mía, aprietas[456 demasiado los hilos.»
UN ESCLAVO.
No tiene aceite la lámpara.
ESTREPSIADES.
¡Ay de mí! ¿Por qué has encendido una lámpara tan bebedora?
Acércate para que te haga llorar
EL ESCLAVO.
Y ¿por qué he de llorar?
ESTREPSIADES.
Por haber puesto una mecha muy gorda... Después, cuando nos nació este hijo, disputamos mi buena mujer y yo acerca del nombre que habríamos de ponerle. Ella le posponía a todos los nombres el de caballo, queriendo que se llamase Jantipo, Caripo o Calípides[457] . Yo le llamaba Fidónides[458] , como su abuelo. Tras largo debate adoptamos, por fin, un término medio y le llamamos Fidípides[459] . Su madre, tomándole en brazos, solía decirle entre caricias: «¡Cuándo te veré, hecho un hombre, venir a la ciudad, ricamente vestido y dirigiendo tu carro, como tu abuelo Megacles...!» Y yo le decía «¡Cuándo te veré, vestido de pieles, traer las cabras del Feleo[460 como tu padre...!» Pero nunca hizo caso de mis palabras. Y su afición a los caballos[461] me ha perdido. Después de haber meditado toda la noche, he encontrado un maravilloso expediente, que me salvará s consigo persuadir a mi hijo. Mas, antes de todo, quiero despertarle ¿Cómo haré para despertarlo dulcemente? ¿Cómo? ¡Fidípides querido Fidípides![462] .
FIDÍPIDES.
¿Qué, padre mío?
ESTREPSIADES.
Bésame y dame tu mano derecha.
FIDÍPIDES.
Hela aquí. ¿Qué ocurre?
Di: ¿me amas?
Sí, por Neptuno ecuestre.
ESTREPSIADES.
FIDÍPIDES.
ESTREPSIADES.
Por favor, no me recuerdes nunca a ese domador de caballos; es la causa de todos mis males. Si me amas de todo corazón, hijo mío compláceme.
FIDÍPIDES.
¿Y en qué quieres que te complazca?
ESTREPSIADES.
Cambia pronto de costumbres, y ve a aprender donde yo te mande.
FIDÍPIDES.
Explícate ya: ¿qué quieres?
ESTREPSIADES.
¿Y me obedecerás?
Te obedeceré, por Baco.
FIDÍPIDES.
ESTREPSIADES.
Mira a este lado. ¿Ves esa puertecita y esa casita?
FIDÍPIDES.
Las veo. ¿Pero qué quiere decir esto?
ESTREPSIADES.
Esa es la escuela[463] de las almas sabias. Ahí habitan hombres que hacen creer con sus discursos que el cielo es un horno que nos rodea y que nosotros somos los carbones[464] . Los mismos enseñan, si se les paga, de qué manera pueden ganarse las buenas y las malas causas.
FIDÍPIDES.
Y ¿quiénes son esos hombres?
ESTREPSIADES.
No sé bien cómo se llaman. Son personas buenas dedicadas a la meditación.
FIDÍPIDES.
¡Ah, los conozco, miserables! ¿Hablas de aquellos charlatanes pálidos y descalzos, entre los cuales se encuentran el perdido Sócrates y Querefonte?[465]
ESTREPSIADES.
¡Eh! calla: no digas necedades. Antes bien, si te conmueven las aflicciones de tu padre, sé uno de ellos y abandona la equitación.
FIDÍPIDES.
No lo haré, por Baco, aunque me dieses todos los faisanes que cría Leógoras[466]
ESTREPSIADES.
¡Oh!, por favor, queridísimo hijo, ve a la escuela.
FIDÍPIDES.
Y ¿qué aprenderé?
ESTREPSIADES.
Dicen que enseñan dos clases de discursos: uno justo, cualquiera que sea, y otro injusto[467]; con el segundo de estos afirman que pueden ganar hasta las causas más inicuas. Por tanto, si aprendes e discurso injusto, no pagaré ni un óbolo[468] de las deudas que tengo po tu causa.
FIDÍPIDES.
No puedo complacerte. Me sería imposible mirar a un jinete s tuviese el color de la cara tan perdido.
ESTREPSIADES.
Por Ceres, no comeréis ya a mis expensas ni tú, ni tu caballo de tiro, ni tu caballo de silla[469] , sino que te echaré de casa enhoramala[470] .
FIDÍPIDES.
Mi tío Megacles no me dejará sin caballos. Me voy, y no hago caso de tus amenazas.
(Aquí debe haber mutación de escena, puesto que Estrepsiades va a llamar en la puerta de Sócrates.)
ESTREPSIADES.
Sin embargo, aunque he caído, no he de permanecer en tierra[471] sino que invocando a los dioses iré a esa escuela y recibiré yo mismo las lecciones. Pero ¿cómo, siendo viejo, olvidadizo y torpe, podré aprender discursos llenos de exquisitas sutilezas? Marchemos. ¿Po qué me detengo y no llamo a la puerta? ¡Esclavo! ¡Esclavo!
UN DISCÍPULO.
¡Vaya al infierno! ¿Quién golpea la puerta?
ESTREPSIADES.
Estrepsiades, hijo de Fidón, del cantón de Cicinno[472] .
EL DISCÍPULO.
¡Por Júpiter! Campesino habías de ser para golpear tan brutalmente la puerta y hacerme abortar[473] un pensamiento que había concebido.
ESTREPSIADES.
Perdóname, porque habito lejos de aquí, en el campo; pero dime ¿cuál es el pensamiento que te he hecho abortar?
EL DISCÍPULO.
No me es permitido decirlo más que a los discípulos.
ESTREPSIADES.
Dímelo sin temor, porque vengo a la escuela como discípulo.
EL DISCÍPULO.
Lo diré: pero ten en cuenta que esto debe de ser un misterio Preguntaba ha poco Querefonte a Sócrates cuántas veces saltaba lo
largo de sus patas una pulga que había picado a Querefonte en una ceja y se había lanzado luego a la cabeza de Sócrates[474] .
ESTREPSIADES.
Y ¿cómo ha podido?...
EL DISCÍPULO.
Muy ingeniosamente. Derritió un poco de cera, y cogiendo la pulga sumergió en ella sus patitas. Cuando se enfrió la cera, quedó la pulga con una especie de borceguíes pérsicos[475] . Se los descalzó Sócrates y midió con ellos la distancia recorrida por el salto.
ESTREPSIADES.
¡Supremo Júpiter, qué inteligencia tan sutil!
EL DISCÍPULO.
¿Pues qué dirás si te cuento otra invención de Sócrates?
ESTREPSIADES.
¿Cuál? Dímela, te lo ruego.
EL DISCÍPULO.
El mismo Querefonte Esfetiense le preguntó si creía que los mosquitos zumbaban con la trompa o con el trasero.
ESTREPSIADES.
¿Y qué dijo de los mosquitos?
EL DISCÍPULO.
Dijo que el intestino del mosquito es muy angosto, y que a causa de su estrechez el aire pasa con gran violencia hasta el trasero, y como e orificio de este comunica con el intestino, el trasero produce e zumbido por la violencia del aire.
ESTREPSIADES.
Por lo tanto, el trasero de los mosquitos es una trompeta. ¡Oh tres veces bienaventurado el autor de tal descubrimiento! Fácilmente obtendrá la absolución de un reo quien conoce tan bien el intestino de mosquito.
EL DISCÍPULO.
Poco ha una salamandra le hizo perder un gran pensamiento.
ESTREPSIADES.
Dime: ¿de qué manera?
EL DISCÍPULO.
Observando de noche el curso y las revoluciones de la luna, miraba al cielo con la boca abierta, y entonces una salamandra le arrojó su excremento desde el techo.
ESTREPSIADES.
¡Linda salamandra que hace sus necesidades en la boca de Sócrates!
EL DISCÍPULO.
Ayer por la tarde no teníamos cena.
ESTREPSIADES.
¡Hem! ¿Y qué inventó para encontrar comida?
EL DISCÍPULO.
Extendió polvo sobre la mesa, dobló una barrita de hierro[476] , y recogiendo después el compás, escamoteó un vestido de la palestra.
ESTREPSIADES.
¿Por qué admiramos ya a Tales?[477] Abre, abre prontamente la escuela, y preséntame a Sócrates cuanto antes. Me impaciento po ser su discípulo. ¡Vivo! abre la puerta. — ¡Oh Hércules! ¿De qué país son estos animales?[478] .
EL DISCÍPULO.
¿De qué te admiras? ¿Con quiénes les encuentras semejanza?
ESTREPSIADES.
Con los lacedemonios hechos prisioneros en Pilos[479] . ¿Pero po qué miran esos a la tierra?
EL DISCÍPULO.
Investigan las cosas subterráneas.
ESTREPSIADES.
Entonces buscan cebollas. No os cuidéis más de eso: yo sé dónde las hay hermosas y grandes. — ¿Y qué hacen esos otros con e cuerpo inclinado?
EL DISCÍPULO.
Investigan los abismos del Tártaro.
ESTREPSIADES.
¿Para qué mira al cielo su trasero?
EL DISCÍPULO.
Es que aprende astronomía por su parte. Pero entrad, no sea que e maestro nos sorprenda.
ESTREPSIADES.
No, todavía no: que estén aquí; tengo que comunicarles un asuntillo mío.
EL DISCÍPULO.
Es que no pueden permanecer largo tiempo al aire y en el exterior.
ESTREPSIADES.
¡En nombre de los dioses! ¿Qué son estas cosas? Decídmelo.
