Evaluating Factors that Affect Construction Project Duration
Abstract
The actual duration of both military and civil works construction projects often differs substantially from the estimates made before construction begins. In fiscal year (FY) 1988, actual duration of military construction projects took an average of 17 percent longer than estimated. Similarly, actual duration of civil construction projects averaged 19 percent longer than estimated. Automatically generated construction schedules may help to quickly produce more accurate estimates of construction duration. Such schedules will require improved activity duration estimates before the start of construction. Recent research has used flexible critical path method (CPM) schedules contained in an artificial intelligence (AI) based programming environment to create or update construction schedules. Durations for individual activities in these networks are based on material quantities, crew formations, and productivity rates, and on other types of building characteristics. When realistic activity durations have been developed, flexible logic between activities provides the basis for the CPM calculation of construction completion. This study incorporates three additional factors that can unexpectedly extend construction activities: (1) work delays, (2) weather delays, and (3) productivity delays. The approach presented in this report may reduce the time required to produce preliminary schedules since the templates used here already contain a significant amount of scheduling knowledge.... Construction scheduling, Critical path method (CPM), Artificial intelligence, Construction duration estimating system (CODES), Control estimate generator (CEG), Computerized cost estimating system (CACES).
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1992
- Accession Number
- ADA259046
Entities
People
- Amr Hassanein
- E. William East
- John Melin
Organizations
- Construction Engineering Research Laboratory