Tuesday, June 23, 2009

Construction Estimating Software


From Wikipedia, the free encyclopedia

Construction estimating software is computer software designed for contractors to estimate construction costs for a specific project. A contractor will typically use estimating software to estimate his bid price for a project owner, which will ultimately become part of a resulting construction contract. Some architects and engineers may also use estimating softare, but usually only to provide a budgetary cost estimate to an owner prior to construction.


Contents


History

Traditional Estimating Methods

Contractors review a project's plans and specifications to produce a takeoff (a list of item and material quantities needed for the project). This is traditionally done by analyzing the project plans and, utilizing knowledge of required construction methods, producing an itemized list of the project requirements. Then, based on this list, a contractor will tabulate the various resources and costs for every aspect of construction. These resource costs include labor, equipment, materials, subcontractors, and any other related costs.

The Rise of Spreadsheets

With the advent of computers in business, contractors began using spreadsheet applications like VisiCalc, Lotus 1-2-3, and Microsoft Excel to duplicate the traditional tabular format, while automating redundant mathematical formulas.[1]

Database Applications Emerge

As more and more contractors came to rely on spreadsheets, and the formulas within the spreadsheets became more complex, spreadsheet errors became more frequent. These were typically formula errors and cell-reference errors. Hard-coded formulas in database applications were originally created to overcome these errors. As these applications became more and more popular over the years, additional features, such as saving data for reuse and construction-specific calculations, have become available.


Typical Software Features

  • Item or Activity List: All estimating software applications will include a main project window that outlines the various items or activities that will be required to complete the specified project. More advanced programs are capable of breaking an item up into subtasks, or sublevels. An outline view of all of the top-level and sub-level items provides a quick and easy way to view and navigate through the project.
  • Resource Costs: Resources consist of labor, equipment, materials, subcontractors, trucking, and any other cost detail items. Labor and equipment costs are internal crew costs, whereas all other resource costs are received from vendors, such as material suppliers, subcontractors, and trucking companies. Labor costs are usually calculated from wages, benefits, burden, and workers compensation. Equipment costs are calculated from purchase price, taxes, fuel consumption, and other operating expenses.
  • Item or Activity Detail: The detail to each item includes all of the resources required to complete each activity, as well as their associated costs. Production rates will automatically determine required crew costs.
  • Calculations: Most estimating programs have built-in calculations ranging from simple length, area, and volume calculations to complex industry-specific calculations, such as electrical calculations, utility trench calculations, and earthwork cut and fill calculations.
  • Markups: Every program will allow for cost mark-ups ranging from flat overall mark-ups to resource-specific mark-ups, mark-ups for general administrative costs, and bonding costs.
  • Detailed Overhead: Indirect costs, such as permits, fees, and any other overall project costs can be spread to project items.
  • Closeout Window: Many estimating programs include a screen for manually adjusting bid prices from their calculated values.
  • Reporting: Project reports typically include proposals, detail reports, cost breakdown reports, and various charts and graphs.
  • Exporting: Most software programs can export project data to other applications, such as spreadsheets, accounting software, and project management software.
  • Job History: Storing past projects is a standard feature in most estimating programs.

References

  1. ^ Christofferson, Jay. "Estimating with Microsoft Excel," Brigham Young University.

External Links


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