Determining Time for completion Construction Projects Using Time List
Authors: Alireza Rezaei, Behnoud Barmayehvar, Alireza Lork  
Published: November 2024

The main text of civil contracts consists of three main parts: the contract’s subject, the contract’s amount, and the contract’s time. Various techniques are used to specify the amounts of civil projects. The most conventional method is using basic price lists published by Iran’s Planning and Budgeting Organization. By the end of the second phase of studies and design and following the completion of all maps and execution details, as well as the specification of the materials to be consumed, the consulting engineer initially determines the volumes of all executive operations from the map and then uses the prices of the items contained in the price lists published by the organization mentioned above to specify the execution price of each of the working items. In the end, the engineer sums up the costs of executing the items and applies the overhead factor to specify the cost of executing the project to initiate the process of tender. 
To determining time for completion the construction project, however, there is no computational technique, and the [time for completion process] is usually performed by the order of the employer or by taking into consideration the construction time of similar projects by the consulting engineers.
One of the techniques to schedule the project is to use the critical path network technique. Project execution time is the sum of the time allotted to perform various working packages within a critical path. The duration of each work package can be determined by using the items that make up that work package. The time to execute each working item involves a probable distribution similar to a normal distribution, and the most probable time to execute an activity is in the middle of a probable distribution diagram.
In the schedule, the duration of the execution of each work package is determined by using the previous experiences of the experts. According to Goldart, when people are asked to estimate the timing of an activity, they apply a safe time to insure themselves against unforeseeable events, though they can perform their activities at shorter times, also .In this study, to determine the execution time of each item included in the price list, the item price breakdown tables that have been published by the Program and Budget Organization have been used, and a list similar to the price list called the time list has been proposed, with the difference that For each item, instead of the implementation cost, the implementation time of that item is included according to the unit of that activity. First, the time list for building items, the price list of mechanical facilities and the price list of electrical facilities have been extracted, and then by using them, the execution time of the items of each work package is determined according to the amount of each item and the number of available resources, and the total times The implementation of work packages is the critical time of project implementation. Finally, the sum of times allotted to execute working packages will be on the critical path of project execution time. It was concluded that time for completion construction project execution by the time list showed a 22.6% reduction [in execution time] compared to the time prediction technique using expert experiences.