Quantitative Techniques for Decision Making in Construction

12.PLANNING AND SCHEDULING DECISION

12.1 Introductio n Completing a project on time, within budget and according to specification s should be the overall objective of a project team . Thi s objective cannot be achieved without proper planning and scheduling. Planning an d schedulin g o f the functions, operation s an d resource s o f a project are amongst the most challenging tasks faced by a project management team. Th e goal is to sequence operations properly and to allocate efficientl y the resources involved. I n this chapter, decision-making aspects of planning and scheduling are discussed. Brie f introductions to various planning and scheduling tool s are also included. Fo r a comprehensive presentatio n of these quantitative techniques readers are referred t o Tang, et al. (2003). 12.2 Plannin g and Schedulin g 12.2.1 Project Planning Planning involves deciding in advance what is to be done, how and in what order, so that the project can be managed effectively . 1 64 QUANTITATIV E TECHNIQUE FOR DECISION MAKING IN CONSTRUCTION • Th e objective of planning is to be able to complete the project effectivel y within a reasonable amount of time, using available resources including money, manpower , material s and equipment . Thu s a well-planne d project would be completed without unusual delay and cost overrun. • Plannin g begins with estimating. The y are simultaneous processes. Jus t as it is necessary to break down a project for the purpose of estimating it is also important to consider a project in parts for the purpose of planning. • Th e real challenge to the project planner/scheduler i s his or her ability to identify all tasks required to complete the project. Bein g able to identify work activitie s an d groupin g the m int o meaningfu l categorie s i s important for planning. Tasks • Plannin g data collection • Plannin g time • Plannin g resources • Plannin g implementation Challenges Where to look for data? What is to be done? What are the activities involved? How can it be done? When is it to be done? Where is it to be done? What is needed to do it? Who is to do it? How to account for performance? How to monitor performance? How to communicate information? Solutions Studying relevant documents Defining scope of work Breaking down the project into activities Developing sequence, network plans Scheduling tasks Charting site layout Forecasting resource requirement Planning manpower requirement Planning materials procurement Planning equipment procurement Budgeting costs Designing organizational structure Allocating tasks and resources Establishing responsibility centers Designing control system Formulating monitoring process Developing project management information system Table 12.1 Projec t planning proces s PLANNING AND SCHEDULING DECISION S 1 6 5 • Th e process of developing a well-defined wor k breakdown structur e (WBS) often leads to a list of activities that must be performed to complete a project. • Projec t planning provides the central communication tha t coordinate s the work of all parties. Planning also establishes the benchmark for the project contro l system to track the quantity, cost, and timing of work required to successfully complet e the project. Example 12. 1 Decision making at the estimating stage Consider the following two line items taken from an estimate worksheet for labour cost only. Item Quantity(tonnes ) 1. Erect structural steel 28 0 2. Erect joist steel 20 0 The estimator/planner must decide one of the following crews, as described below, to use for the two tasks. Crew 1 Cre w 2 1 foreman @$65.0 0 4 iron-workers @$50.0 0 1 operator @$45.0 0 1 oiler @$40.0 0 2 labourers @$35.0 0 Total 9 crew-hours Unit crew price = $46.67 $65.00 200.00 45.00 40.00 70.00 $420.00 1 foreman @$65.0 0 5 iron-workers @$50.0 0 1 operator @$45.0 0 1 oiler @$40.0 0 3 labourers @$35.0 0 Total 11 crew-hours Unit crew price = $45.91 $65.00 250.00 45.00 40.00 105.00 $505.00 Production Rates (tonne/day) Cre w hours Item Cre w 1 Cre w 2 Cre w 1 Cre w 2 1. Erect structural steel 10. 4 12. 3 1960 * 200 3 2. Erect joist steel 14. 4 16. 1 100 0 109 3 * Explanation: 10.4/ 8 = 1.3 tonne/hr; (1/1.3...