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Counting bricks In this current climate of austerity, with its drive to make projects more efficient, it is more important ithan ever to ensure that cost estimates are accurate

Selecting elements in a BIM/IFC model


ne of the most common phrases in any construction project has to be 'How far over budget are you?' In fact, it is almost an accepted position that the final cost of a project will be some way over the initial estimated cost. And that is in spite of all of the project and financial management tools that we bring to bear on the subject. The problem is that, lacking a suitable dedicated solution, contractors have relied on the good old Excel spreadsheet - a curse as much as a blessing, as the effort involved in setting up and maintaining a complex spreadsheet tended to exhaust the originator, and precluded them from exploring the deeper reaches of its capabilities, or the possibilities that could be found with other systems. Excel spreadsheets tend to be realtime systems, and don't provide easy access to historical data, or the means to use that data to qualify current information and to make value judgements on it. They force operators to undertake much repetitive work, and manual re-entry, leading to errors, or to create complex macros that can be ultimately deciphered solely by their creators. The above problems exist because Excel is not a database, and if users try to use it as one they’ll find that it has some severe

30 November/December 2010

Adding BOQ items from a resource database limitations. And yet in spite of all this Excel is still the tool of choice for many companies doing cost estimating.

WHAT IS COST ESTIMATING? To get down to real basics, cost estimating is the counting of how many bricks you require to build a wall, the cost of labour to build it, and equipment and other costs associated with the job - material, labour, equipment, subcontractor and consumables. These are pretty much the same around the country - except of course for London, where costs tend to be rather higher than they are in Somerset and are classed as resources. Resources are held on Relational Resource Cost Databases, and can be applied to any application that can present it with quantities and volumes to come up with accurate estimation of costs. One such application is CostOS, developed by Nomitech. Recognising the need for an effective estimating system for the construction industry, Nomitech, founded in 2005, has brought together specialists in software development, AEC and EPC project management, planning and contracting to develop a powerful solution that would lead the market. The company also works with leading universities to hone its estimating product

further, and to date has supplied major European PPP projects and a number of oil and gas projects in the Middle East. Today the estimating suite, CostOS, is sold in 15 countries around the world, and its implementations are expanding fast. CostOS Estimating has been designed to streamline the estimating process, locating and extracting costs from the millions of historical entries in such databases (by utilising Google-type algorithms) to provide planners with a solid cost basis for their plans - and, of course, to resolve the limitations of MS Excel spreadsheets. It allows users to assign resources and create WBS and Group codes, using artificial intelligence to simplify and speed up the process of building project related resource databases. CostOS also works over the web, so that teams of estimators can work on projects, with refinements, such as colour-coding of BOQ items, roles of users and statistics to facilitate rapid assimilation of data. To provide a complete solution from design to implementation of a project, CostOS is able to work directly with both 2D drawings and 3D models, extracting the quantities that are required to calculate costs. At the other end, it can be set up to interact with project planning solutions such as Oracle's Primavera, or Asta Power

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CostOS working in conjunction with Primavera 6

Selecting BOQ items from a BIM/IFC model Project - to provide additional planning information and get updated by the project plan, so that, for instance, extended deadlines with increased labour resource requirements can be brought into the planning calculations, or new quantities that are brought into the estimate can be reflected in the project's total duration.

MAINTAINING DATABASES There are a number of organisations that develop and maintain cost databases, such as Reeds (RS Means) Database, Richardson's, Spon's and NODOC, etc. Using these databases through CostOS enables you to keep track of costs, utilising CostOS's powerful search engines to find priced items and, if necessary, allow them to be amended to suit a particular project's needs. Such databases store large amounts of historical data, and can also be used by companies to build their own cost databases. Nomitech, realising the value of such relational cost resource databases and the need to keep them constantly updated for its customers, does it all for you - an otherwise onerous task if you rely on your own data or an Excel spreadsheet. Databases that are resource related, like those above, can also be applied internationally, with estimators able to amend the productivities, salaries, material prices and even currencies and apply them in each country. CostOS also takes into account the local fuel prices and accurately calculates the equipment operating costs, which play a major role in heavy civil projects. Users also have the ability to accurately calculate their equipment depreciation costs, and make predictions of future material and subcontractor prices based on trends created on their historical data.



Now we come to the nitty-gritty. Having ensured that costs can be calculated using up-to-date resource/cost databases, we need to ensure that resources and materials reflect the current state of the design - or the project. That is, we need to ensure that the estimate and the schedule are in sync with each other. Estimates can be imported into Primavera as resource-loaded lists of activities with activity durations, WBS codes and budgeted units, so that planners can start putting in the logic that drives the project plan, or Primavera Projects can be loaded into CostOS for the estimators to start calculating the costs. However, utilising the benefits of BIM, we can go one step further. Having previously developed the integration with On Center's 2D cost Takeoff tool, with which estimators could perform Takeoffs from PDF or DWG files and store the quantities in the On-Screen Takeoff database, subsequently linking the quantities with the estimate, Nomitech now enables estimators to work on a 3D model and read-off the resources and the cost required to build it - a cost-loaded 3D model! Estimating directly on the model dramatically reduces the time it takes to provide a detailed estimate - and we are talking minutes, instead of days! With just a couple of clicks, estimators can pick up quantities of materials from all the leading BIM systems, ArchiCAD, Autodesk Revit, Bentley Architecture and AllPLan processes that normally take hours of manual effort. Using CostOS with On-screen Takeoff enables changes to the design that affect resources to be implemented immediately, at the click of a button - and if CostOS is also integrated with a Project Planning system they will be reflected there as well.

Almost all general contractors' tendering departments spend about 40% of their time speaking with subcontractors and suppliers asking them to submit their offers on the projects they are about to bid. This information is usually lost after the tender is submitted in the case of lost bids. CostOS's latest version, 3.8, streamlines this process and allows this effort to become a knowledge base for next bids. The estimators have the ability to automatically create emails with Request for Quote (RFQ) in Excel format and send them to subcontractors or suppliers that are kept in their database. There is a "pending flag" next to the supplier/ subcontractor on these BOQ items until the latter's Quote is received. In that case the user can manually award winning quotes, or do it automatically based on criteria such as lowest quote, median, or based on the supplier's/subcontractor's ranking. These quotes are also stored in the database as resources and estimators can refer to them and even create trends based on their data. Very large estimates with thousands of items can be completed very easily, and more importantly in a well organised and consistent manner. This leads us into an unusual situation planners and estimators being able to sit down together and work out the effect of design changes on resources, materials and ultimately costs, providing the tools that they need to make strategic decisions and keep their project in budget. And why stop there? Clients can be invited along to planning sessions to view the 3D model, enabling them to see at first hand what their proposed modifications would do to the cost of the project, as well as to the time scale needed to construct it.

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Nomitech CostOS BIM Estimating Article by CAD user magazine  

Selecting eelements iin aa BBIM/IFC mmodel Adding BBOQ iitems ffrom aa rresource ddatabase WHAT IIS CCOST EESTIMATING? limitations. And yet...

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