Building Project Activities/Tasks Time Scheduling using a Linear Programming Model

Abstract

The problem with the management of construction works is the ability to create a good work breakdown structure (WBS); determine inter-relationship among tasks; determine duration for each of the tasks and to create a workable schedule. Most locally handled construction work always experience such problems as: increase cost of project work; project work not delivered within the expected time (schedule slippage); resource constraint (limitation) etc. This study involves data collection from project supervisor; identification of the activities/tasks in the project; precedence relationship amongst the activities/tasks; developed a network diagram; formulate the Linear programming Model of both the earliest start time (EST) and the latest start time (LST); solve the model using TORA to Obtain the EST and LST of each activity/Task of the Project; determine the activities/tasks which are critical to the timely completion of the project; float for activities/tasks in the project. The result shows that the expected completion time for the project is 210 days (30 weeks) and the critical activities are activity X₁-X₂-X₃-X₄-X₅-X₇-X₈-X₉-X₁₀-X₁₂-X₁₉-X₁₄-X₁₇-X₂₀ {site clearing; setting out; foundation excavation; blinding; block work to DPC; filling and compaction of DPC; mass concrete slab; block work to final level; roofing/roof covering; ceiling finishing; electrical fittings; floor screeding;   painting internal/external walls; commissioning} The Non critical activities are Construction of isolated column base (X₆), Installation of doors and windows frame (X₁₅), Installation of blackboards (X₁₆), Installation of doors and windows (X₁₈) and their “total float” is  4, 3, 7 and 4 days respectively.

Keywords: Task time, Precedence relationship, Project scheduling, linear programming method, work breakdown structure