Cost Estimation Practice

with time, facilities, and costs are available. Contractors in this case not have enough time to estimate costs accurately, facilities to support the activities of these estimates are still less included software facilities, and costs required to meet the facility is considered too great, one of which caused no inability to buy the software cost estimation.

In the implementation cost estimate, there are other constraints felt by small contractors, especially related to the estimation calculation process that is associated with a determination coefficient of the work. This means that small contractors have difficulty in estimating the productivity of the work that is usually obtained from the data of experience in the field. Another difficulty is in the process of analyzing the unit price, it relates directly to the coefficient of workers but broader in scope with the final result to the price of an item per unit volume. Furthermore, the results of a survey that describes the practice of the estimated cost carried out by small contractors are as follows:

1. Volume of work obtained by contractors usually sourced from the owner and also the calculation of the results of its own. This occurs because the type of contract commonly used type of a lumpsum contract, where the volume of work had been predetermined by the owner as a reference.
2. In estimating the volume of material is wasted, a small contractor to do it by referring to the percentage volume of these materials on a job, applying it to all types of the same material on another job, and using the percentage of work items without more detailed analysis
3. Small Contractor codefication item does not have a standard job. This is due to ignorance of the benefits codefication themselves for the benefit estimates and other related applications.
4. All the respondents conducted a survey of prices in each plan cost estimates. About 50% of respondents obtain new price information from suppliers and the majority of small contractors to do the survey every new project. Items that are always updated are certain items related to the project.
5. All respondents to analyze the productivity of workers and always items documented to be used as reference in subsequent project work.
6. Update productivity data made where there is a new project. Listing of productivity per job done, meaning that the respondents noted a work productivity in the form of a crew of workers for certain jobs.
7. For indirect costs are taken into account by the contractor is the cost of overhead, contingency, profit, and tax and insurance costs on the project.
8. All respondents take into account the overhead costs that are inserted in the percentage of total project cost.
9. All respondents take into account the profit, profit insertion there are two alternatives, among others, the cost per job or on overall costs. Profit will be calculated after all indirect costs included, usually profit calculations are shown in the list offering price (not inserted as other indirect costs).
10. All respondents take into account the tax cost on the project especially on the workers, the insertion fee percentage tax on the total project cost. Tax calculation results are usually not inserted yet shown in the report, the percentage of tax taken from the direct costs, indirect costs, and profit.