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Unit Number and Title

9: Software Development Lifecycles

Academic Year

2018

Unit Tutor

Dr. Le Van Minh

Assignment Title

Assignment 2: Undertake a Software Development Lifecycle

Issue Date Submission Date

24/12/2018

IV Name & Date

Nguyen Dinh Quoc Khanh

Learning Outcomes and Assessment Criteria Pass

Merit

Distinction

LO3 Undertake a software development lifecycle P5 Undertake a software investigation to meet a business need.

M3 Analyse how software requirements can be traced throughout the software lifecycle.

P6 Use appropriate software analysis tools/techniques to carry out a software investigation and create supporting documentation.

M4 Discuss two approaches to improving software quality.

D3 Critically evaluate how the use of the function design paradigm in the software development lifecycle can improve software quality.

LO4 Discuss the suitability of software behavioural

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design techniques P7 Explain how user and software requirements have been addressed.

M5 Suggest two software behavioural specification methods and illustrate their use with an example.

D4 Present justifications of how data driven software can improve the reliability and effectiveness of software.

M6 Differentiate between a finite state machine (FSM) and an extendedFSM, providing an application for both.

Assignment Brief Base on the scenario described in the Assignment 1 you need to prepare some tasks: Task1(P5): In order to satisfy the Tune Source’s requirements, choose an appropriate technique(s) such as Interview, questionnaires, JAD, observation… to find out the business requirements. Explain in detail how those techniques should be carried out.

Expected evidences: the reasons for selected techniques, content of the questions, the processes involved.

Task 2(P6):  

Identify stakeholders, costs, security considerations, legacy system of Tune Source.

Base on the requirements found in Task 1 provided presentations for the the following points, use appropriate software techniques such as: Use case diagram, DFD diagrams for modelling the requirements.

Task 3(P7): Select 2 use cases from Task2 and implement it by C# programming language. Explain how the program matches the use case specification.

Task 4 (M3): Analysis how software requirements can be traced throughout the development of Tune 2|Page

Source. The discussion should cover the following topics: Traceability, Baseline, Change management, Tools.

Task 5(M4): Suggest 2 approaches for improving software quality of Tune Source for example: Total Quality Management(TQM) and Test Driven Development(TDD) Task 6(M5): Using Flowchart and Pseudo code to describe 2 any functions in Tune Source.

Task 7(M6): From Tune Source project create a finite state machine (FSM) and an extended-FSM to describe the states of the application for example subscribed and unsubscribed user.

Task 7(D3): Assume that you would use Function-Oriented Design approach to design the Tune Source. Critically evaluate how this approach would help improving software quality.

The discussion should focus on the activates of Function-oriented Design: Data flow design, structure decomposition, Detailed design.

Task 8(D4) Assume that you would use Data Driven approach to design the Tune Source. Critically evaluate how this approach would help improving the reliability and effectiveness of software

Submission Format The submission is in the form of 1 document You are required to make use of headings, paragraphs, subsections and illustrations as appropriate, and all work must be supported with research and referenced using the Harvard referencing system.

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Contents 1 LO3 Undertake a software development lifecycle ................................................................................. 5 1.1 P5 Undertake a software investigation to meet a business need. ................................................. 5 1.2 P6 Use appropriate software analysis tools/techniques to carry out a software investigation and create supporting documentation. ................................................................................................. 6 1.2.1 Development Costs:.................................................................................................................... 6 1.2.2 Security considerations: ............................................................................................................ 7 1.2.3 Use case: ...................................................................................................................................... 7 1.2.4 Use Case Diagram: .................................................................................................................... 11 1.2.5 DFD for Tune Source Process ..................................................................................................... 11 2 LO4 Discuss the suitability of software behavioral design techniques .................................................... 15 2.1 P7 Explain how user and software requirements have been addressed.......................................... 15 2.1.1 Use case name: Create new account: ........................................................................................ 15 2.1.2 : Use case name: Login ............................................................................................................... 18 2.2 M3 Analyse how software requirements can be traced throughout the software lifecycle. ........... 21 2.3 M4 Discuss two approaches to improving software quality............................................................. 23 2.3.1 Using Quality considerations e.g. Total Quality Management (TQM). ...................................... 23 2.3.2 Using Test Driven Development............................................................................................. 24 2.4 M5 Suggest two software behavioural specification methods and illustrate their use with an example................................................................................................................................................... 25 2.5 D3 Critically evaluate how the use of the function design paradigm in the software development lifecycle can improve software quality. .................................................................................................. 28 2.6 D4 Present justifications of how data driven software can improve the reliability and effectiveness of software. ..................................................................................................................... 29 3 Bibliography ............................................................................................................................................. 31

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1 LO3 Undertake a software development lifecycle 1.1 P5 Undertake a software investigation to meet a business need.

In any software development process, we should start with the requirement gathering.

From the requirement gathering we can understand their needs and problems. There are lots of techniques for requirements gathering as Interviews, Questionnaires, conduct a brainstorming session, talk to support team, conduct workshops, Work in the target environment and Look at unintended uses, etc. but we have used Investigative techniques for this requirements gathering.

Investigative techniques include: o Analyzing existing documents Reviewing the current process and documentation can help the analyst understand the business, or system, and its current situation.

The analyst may find there was missing information in old documents.

They may also find redundancy, in which steps are unnecessarily repeated.

Such documentation (if it exists) could include interface details, user manuals, and software vendor manuals. o Questionnaires Questionnaires can be useful for obtaining limited system requirements details from users / stakeholders, who have a minor input or are geographically remote.

Advantages: o Can send to many hundreds of users at a low cost. o Good for getting input from users who are a long distance away. o Receive written replies which can be easier to work with and analyze, and save time typing.

Disadvantages: o Questionnaires can be slow to create. o You may not get a good response, as filling in questionnaires is often a low priority for many people.

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These are the questions we asked the employees about the existing system Underline the suitable answers (Only if you have used the system) 1. How pleased are you with the manual system?

• • • •

Very satisfied Satisfied Good Not satisfied

2. Have any experience using a computer system?

• •

Yes No

3. How well the manual system make the day today task efficient?

• • •

Satisfying Good Bad

4. Howl long it will take to finish one task?

• • •

Short period of time Normal period of time Time consuming

5. Does this system update?

• • •

Not at all Each year Each month

1.2 P6 Use appropriate software analysis tools/techniques to carry out a software investigation and create supporting documentation.

Stakeholder in TuneSource Project: Carly Edwards, Assistant Vice President, Marketing 1.2.1 Development Costs:

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Development Costs 2 Servers @ $125,000

$ 250,000

Printer

$ 100,000

Software licenses

$ 34,825

Server software

$10,945

Development labour

$1,236,525

Consultant fees

$50,000

In-store kiosks

$25,000

Total

$1,707,295 Table 1: Demonstrate the cost of project development.

1.2.2 Security considerations: Safety Requirements Use of this software system is only a solution to Tune Source and management of the data. Safety of the product and its users and moral matter should be given deliberation when using this system. Data could be lost, damaged or injured due to the virus or technical failures. Therefore, we are taking quantifies to avert these hazards.

The limitation takes consequence on shaping the software to be more dependable, reliable and genuine. Back-up and restoration of data as required by the client to avert the loss of data from unforeseen database smack into and keep away from the building up of data which would influence the performance of the system. In the situation where the current goes suddenly then the so far works are save dib log file so in the way of safety also this software in a good position.

System Value: No special system value requirements are anticipated.

Access Control : Customers can access their accounts with username and password.

Encryption/Authentication: Customer payment information must be transmitted securely.

Virus Control: Downloads must be verified as virus free.

1.2.3 Use case: 1.2.3.1 Authenticate user Use case name:

Authenticate user

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Pre-conditions:

System is up and running.

1. The use case begins when the system

Main success scenario:

prompts for username and password.

2. User enters their respective username and password.

3. System validates the input fields.

The use case ends when the system displays the welcome home page and redirects to the relevant user Main page.

3a). System identifies that the username or

Extensions

password is wrong.

3b). System generates an error message notifying login failure.

3c). User is prompted again to re-enter username or password.

3d). Return to main step 3).

1.2.3.2 Search Use Case Name:

Search

System is up and running.

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Pre-Conditions: User has successfully logged into the system.

Use case begins when the user enters the 1) “Search” interface.

The search fields are displayed in a drop-down 2) list and Main Success Scenario:

user selects the search field.

User enters a key word to be searched and 3) presses the “Search” button.

Use case ends when the search results are 4) displayed.

Extension:

If there are no results, a message is displayed.

1.2.3.3 Purchase item Use case name:

Purchase item

Pre-conditions:

System is up and running.

User has successfully logged into the system.

Main success scenario:

1The use case begins when the user enters the relevant interface to see the data.

2. Users choose the song they want to buy 3.User clicks “Pay” button.

4. The system validates the data.

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5. Data is saved to the database and the use case ends.

1The use case begins when the user enters the Extensions:

A successful message inventory has update

1.2.3.4 Create a new account Use case name:

Create new account

Pre-conditions:

System is up and running.

User has successfully logged into the system

Main success scenario:

1The use case begins when the user enter the relevant interface to enter the data.

2.User inputs the details to the fields.

3.User clicks “proceed” button.

4.System validates the data.

5.new profile created

Extensions:

New account has been created or error message

1.2.3.5 Login Use case name:

Login

Pre-conditions:

System is up and running.

Main success scenario:

1.This use case starts when a user wishes to log into the Tune Source System.

2.The system requests that the user enter his/her name and password.

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3.The User enters his/her name and password.

4.The system validates the entered name and password and logs the actor into the system.

Extensions:

If the use case was successful, the user is now logged into the system. If not the system state is unchanged.

1.2.4 Use Case Diagram:

Figure 1: Tune Source Digital Music Download System Use Case Diagram (Dennis, 2015) 1.2.5 DFD for Tune Source Process

Create the level 0 DFD by integrating the DFD fragments, which proved to be anticlimactic.

The team simply took the DFD fragments and drew them together on one piece of paper.

Although it sometimes is challenging to arrange all the DFD fragments on one piece of paper, it was primarily a mechanical exercise (Figure 1).

A careful review of the data stores in Figure 1 reveals that everyone has both an inflow and an outflow, with one exception, D1: Available Tunes. D1: Available Tunes is read by two processes, but is not written to by any process shown. This violation of DFD syntax needs 11 | P a g e

to be investigated by the team because it may be a serious oversight. As we will explain later, in this situation we need to create a process specifically for adding, modifying, and deleting data in D1: Available Tunes. “Administrative” processes such as this are often overlooked, as we initially focus on business requirements only, but will need to be added before the system is complete.

Figure 2: Tune Source Level 0 DFD (Dennis, 2015)

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Figure 3: Level 1 DFD for Tune Source Process 1: Search and Browse Tunes (Dennis, 2015)

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Figure 4: Level 1 DFD for Tune Source Process 2: Purchase Tunes (Dennis, 2015)

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Figure 5: Level 1 DFD for Tune Source Process 3: Promote Tunes (Dennis, 2015)

2 LO4 Discuss the suitability of software behavioral design techniques 2.1 P7 Explain how user and software requirements have been addressed.

2.1.1 Use case name: Create new account: The new user account creation function is written in C #

public UserAccount CreateAccount(NewAccount newAccount) { if (!AccountAlreadyExists(newAccount.UserName)) { var accountBuilder = new AccountBuilder(newAccount); Account account = accountBuilder.CreateAccount(); db.Entry(account.UserAccount).State = EntityState.Added; 15 | P a g e

db.Entry(account.Contact).State = EntityState.Added; db.Entry(account.User).State = EntityState.Added; db.SaveChanges(); return account; } return null; } internal class UserAccountBuilder { private readonly NewAccount _newAccount; public UserAccountBuilder(NewAccount account) { _newAccount = account; } public Account CreateAccount() { return new Account( CreateUserAccount(), CreateUser(), CreateUserContact() ); } private string GetUsername() { return _newAccount.UserName; } private UserAccount CreateUserAccount() { string salt = StringCipher.GenerateCypher(); return new UserAccount() { UserId = GetUsername(), PasswordHash = CreatePasswordHash(_newAccount.Password), Lock = true, Created = DateTime.UtcNow }; 16 | P a g e

} private User CreateUser() { return new User() { UserId = GetUsername() }; } private UserContact CreateContact() { return new UserContact() { ContactTypeId = ContactType.EmailPrimary, Contact = StringCipher.Encrypt(_newAccount.UserEmail, salt), UserId = GetUserName(), Active = true, Created = DateTime.UtcNow } } } public class Account { public UserAccount Account { get; private set; } public User User { get; private set; } public UserContact Contact { get; private set; } public Account( UserAccount userAccount, User user, UserContact userContact) { Account = userAccount; User = user; Contact = userContact; } } }

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After building the algorithms in C # and using the tools to create the interface we will get an interface that functions like this.

Figure 6 : Interface of Create New Account Function

2.1.2 : Use case name: Login Code C#:

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; using System.Data.SqlClient;

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namespace First_Csharp_app { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { try { if (!(usertxt.Text == string.Empty)) { if (!(passtxt.Text == string.Empty)) { String str = "server=MUNESHPC;database=windowapp;UID=sa;password=123"; String query = "select * from data where username = '" + usertxt.Text + "'and password = '" + this.passtxt.Text + "'"; SqlConnection con = new SqlConnection(str); SqlCommand cmd = new SqlCommand(query, con); SqlDataReader dbr; con.Open(); dbr = cmd.ExecuteReader(); int count = 0; while (dbr.Read()) { count = count + 1; } if (count == 1) { MessageBox.Show("Username and password is correct"); } else if (count > 1) { MessageBox.Show("Duplicate username and password", "Login page"); } else { 19 | P a g e

MessageBox.Show(" Username and password incorrect", "Login page"); } } else { MessageBox.Show(" Password empty", "Login page"); } } else { MessageBox.Show(" Username empty", "Login page"); } // con.Close(); } catch (Exception es) { MessageBox.Show(es.Message); } } } Login interface of the site:

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Figure 7: Interface of Login Function.

2.2 M3 Analyse how software requirements can be traced throughout the software lifecycle.

Once the Tune Source approval committee approved the system request and feasibility analysis, the project team began performing analysis activities. These included gathering requirements by a variety of techniques and analyzing the requirements that were gathered. Some highlights of the project team’s activities are presented next. Eliciting and Analyzing Requirements Jason believed that it would be important to understand the current Web-based sales processes and systems that already existed in the organization, because they would have to be closely integrated with the Digital Music Download system.

Two requirements-gathering techniques proved to be helpful in understanding the current systems and processes—document analysis and interviews.

First, the project team collected existing reports (e.g., sales forms, screen shots of the online sales screens) and system documentation (data models, processmodels) that shed light on 21 | P a g e

the as-is system. They were able to gather a good amount of information about the existing order processes and systems in this way. When questions arose, they conducted short interviews with the person who provided the documentation, for clarification.

Next, Jason interviewed the senior analysts for the current sales systems to get a better understanding of how those systems worked. He asked whether they had any ideas for the new system, as well as whether there were any integration issues that would need to be addressed. Jason also interviewed a contact from the ISP and the IT person who supported Tune Source’s current Web site—both provided information about the existing communications infrastructure at Tune Source and its Web capabilities. Carly suggested that the project team conduct several JAD sessions with store managers, marketing analysts, and Web-savvy members of the IT staff. Together, the groups could brainstorm the features desired in the Digital Music Download system. Jason facilitated three JAD sessions that were conducted over the course of a week. Jason’s past facilitation experience helped the eight person meetings run smoothly and stay on track. Because this project introduces a new business process, Jason used technology analysis and suggested several important Web technologies that could be used for the system. The JAD session generated ideas about how Tune Source could apply each of the technologies to the Digital Music Download system. Jason had the group categorize the ideas into three sets: “definite” ideas that would have a good probability of providing business value, “possible” ideas that might add business value, and “unlikely” ideas.

Next, Jason applied informal benchmarking by introducing the Web sites of several leading retailers and pointing out the features that they offered online. He selected some sites on the basis of their success with Internet sales, and others on the basis of their similarity to the vision for Tune Source’s new system. The group discussed the features that were common across most retailers, versus unique functionality, and they created a list of suggested business requirements for the project team.

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Figure 8: Tune Source Requirements Definition

2.3 M4 Discuss two approaches to improving software quality.

To improve the software quality of Tune Source, we can use quality approach and management processes such as: 2.3.1 Using Quality considerations e.g. Total Quality Management (TQM).

TQM is a management approach aimed at satisfying all the customer requirements, needs and expectations using a continuous improvement approach There are three aspects of software quality:  

functional quality, structural quality 23 | P a g e



process quality

However, the quality of software is estimated by many of its attributes such as reliability, integrity, maintainability, enhance ability (extensibility), usability, portability, and reusability The functionality of the software and the appearance of the user interface could also affect software quality. Consequently, these characteristics can affect user satisfaction so it could be used as a measure of software quality.

Functional quality means that the software performs the tasks it is intended to do for its users correctly. Software testing commonly focuses on functional quality.

The second aspect of software quality, structural quality, means the code itself is well structured. Unlike functional quality, structural quality is hard to test for.

The third aspect, process quality, it is the quality of the development process significantly affects the value received by users, development teams, and sponsors, and all three groups have a stake in improving software quality.

2.3.2 Using Test Driven Development TDD (Test Driven Development) is a working method or a modern coding process.

Programmers will perform through BabyStep and progress is guaranteed continuously by writing and running automated tests. The programming process in TDD is extremely focused on the following continuous steps: 1. Write a test for the new function. Make sure the test will fail.

2. Switch to writing the most primitive code for that function to test if it can pass.

3. Optimize the code of the newly written function to ensure the test is still pass and optimized for the next programming 4. Repeat for other functions from step 1

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Figure 9: A cycle when applying TDD

2.4 M5 Suggest two software behavioural specification methods and illustrate their use with an example.

We have two software behavioral specification methods are: Flowchart: A flowchart is a diagram that depicts the “flow” of a program.

Pseudocode: is a newer tool and has features that make it more reflective of the structured concepts.

Illustrate their use with some example: Function :Log In Draw a flowchart to log in to Tune Source account:

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Figure 10: Flowchart function Log in Pseudocode: 1.

2.

3.

4.

Enter www.TuneSource.com in your browser. (I/O) TuneSource Home page loads (PROCESS) Enter your Email ID and Password (I/O) Is Email ID and Password Valid (DECISION) if NO then Log in error (PROCESS) go to step 3 else Display Account (I/O) Stop

Function: Find Tune by Title

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Figure 11: Program Specification for Find Tune by Title (Dennis, 2015)

M6 Differentiate between a finite state machine (FSM) and an extended- FSM, providing an application for both.

A finite-state machine, or FSM for short, is a model of computation based on a hypothetical machine made of one or more states. Only a single state can be active at the same time, so the machine must transition from one state to another in order to perform different actions. FSMs are commonly used to organize and represent an execution flow, which is useful to implement AI in games.

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Extended Finite State Machines (EFSMs) provide a powerful model for the derivation of functional tests for software systems and protocols. Many EFSM based testing problems, such as mutation testing, fault diagnosis, and test derivation involve the derivation of input sequences that distinguish configurations of a given EFSM specification.

A finite state machine is just a free user state in the TuneSource system. Free users are allowed to use basic functions without paying. But of course, there will be a limit to some extent.

An extended finite state machine is a premium user status in the TuneSource system. In this state, paid users will be able to use all the functions available in the TuneSource system without being limited by anything.

Finite state machine (User free)

Extended- FSM(Premium users)

Price 0$ / month

Price 3$ / month

Automatically shuffle song lists

Non Automatically shuffle song lists

There are ads

No ads

Do not allow listening offline

Allow listening offline

No high sound quality

High sound quality

Table 2: The expansion varies between premium users and free users.

2.5 D3 Critically evaluate how the use of the function design paradigm in the software development lifecycle can improve software quality.

The first thing Object-oriented Paradigm provides is flexibility, efficient coding or programming and also easy to debug the existing codes.

Here are the main three arguments are provided why OOP is better to use over classical paradigm: Improving the software development productivity: - the Object-oriented paradigm can be used as a modular function which will provide each code into a separate module in the development of the programming. The main feature is that the object can be included with new attributes as well as behaviors. The object can be reused within other applications.

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Thus, it provides reusability, extensibility, and modularity, these 3 factors typically make the program more productive than the other classical method.

The productivity of higher quality software: - With the involvement of faster development and also lowering the cost of the software development, Object-oriented paradigm provides time as well as a resource that can be used for authentication purpose.

Based on the quality, companies are switching to OOP over the classical paradigm and the result also leads to high-quality software production.

Software maintenance: - Object-Oriented paradigm provides a huge scope of maintaining and operating the software easily. The code can be debugged easily as each module perform a different operation. Thus, in order to fix the functionality of the software, you don’t need to check the whole code, only fixing the particular module will work for you.

So, I hope these 3 arguments will certainly be helpful for you to use to the Object Oriented Paradigm.

2.6 D4 Present justifications of how data driven software can improve the reliability and effectiveness of software.

A data–driven software: • Automates processes, problems, and opportunities • Operates on diverse data from many multichannel data sources • Makes information universally available within a single application • Seamlessly combines operational and analytic capabilities • Automatically generates master data, metadata, models, schema, and graphs as the user searches, queries, and collects data • Continuously correlates data entities (e.g. people, products, places, organizations) into 360–degree views that can be pivoted from any perspective In short, if you use the data-driven method to design and develop TuneSource you will be: 1) It can help you make more informed design decisions.

The nice thing about using data to drive design is that it gives you more information about what works and what falls flat. Often in the design process, gut feelings and personal preference can take priority over rational design decision making. If you’ve got both quantitative and qualitative data to back up your design choices, in theory the best decision should be obvious. The better the data you’ve collected, the better the decisions you can make (to a point).

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2) It lets you track changes over time.

Whenever you make a change to your site’s design, you don’t want it to be a shot in the dark. Collecting data after you do something like changing a design feature will tell you whether the changes you’ve made are working, and it’ll help you understand better what your users respond to and what they don’t.

In theory, this should also help you out with the first point on this list – if you’ve been gathering data for a long time and tracking the changes you make, you’ll be able to make more informed decisions.

3) It can help you find problems and their solutions.

Pinpointing a problem area on your site is next to impossible without robust data. Maybe you’re not getting the conversions you thought you would, or your users are dropping off at some point on the customer journey – but you’ll never know exactly what’s going on until you have the data (both quantitative and qualitative) to tell you.Data will also make finding a solution to that problem a whole lot easier.

First off, knowing specifically what is happening and why makes it possible to come up with solutions that are specific and targeted.

Second, once you’ve come up with a few solutions, you can use data to test out which solution best solves the problem, and go from there.

4) It’ll help you get to know your users better.

At the end of the day, connecting with your users and giving them a better experience should be the goal of your site. It’s what everything else, from sales to sign-ups, stems from, so getting to know your users should be a top priority.

Good data can tell you a lot about your users – their preferences, their behavior, their particular reactions to various pieces of site content – and help you to make design situations that suit them moving forward.

Major problems emerge when you design for who you think your users are, and not who they really are. And the only way to find out who they really are is to collect good quantitative and qualitative data.

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3 Bibliography Buglione, Luigi and Abran, Alain, 2007. Improving Estimations in Agile Projects: issues and avenues. s.l.:s.n.

Dennis, A. B. H. W. a. D. T., 2015. Systems analysis and design. Fifth Edition ed. s.l.:John wiley & sons.

Everett, Gerald D and McLeod Jr, Raymond, 2007. Software testing: testing across the entire software development life cycle. s.l.:John Wiley \& Sons.

McConnell, 1996. Rapid development: taming wild software schedules.. s.l.:Pearson Education..

Mishra, Apoorva and Dubey, Deepty, 2013. A comparative study of different software development life cycle models in different scenarios. s.l.:International Journal.

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