Sunday, July 5, 2009
PERT (program evaluation
and review technique) and CPM (critical path method), are available to assist the
project manager in carrying out these responsibilities. These techniques make heavy use
of networks (as introduced in the preceding chapter) to help plan and display the coordination
of all the activities. They also normally use a software package to deal with all the
data needed to develop schedule information and then to monitor the progress of the project.
Project management software, such as MS Project in your OR Courseware, now is
widely available for these purposes.
PERT and CPM have been used for a variety of projects, including the following types.
1. Construction of a new plant
2. Research and development of a new product
3. NASA space exploration projects
4. Movie productions
5. Building a ship
6. Government-sponsored projects for developing a new weapons system
7. Relocation of a major facility
8. Maintenance of a nuclear reactor
9. Installation of a management information system
10. Conducting an advertising campaign
A Gantt chart is constructed with a horizontal axis representing the total time span of the project, broken down into increments (for example, days, weeks, or months) and a vertical axis representing the tasks that make up the project (for example, if the project is outfitting your computer with new software, the major tasks involved might be: conduct research, choose software, install software). Horizontal bars of varying lengths represent the sequences, timing, and time span for each task. Using the same example, you would put "conduct research" at the top of the vertical axis and draw a bar on the graph that represents the amount of time you expect to spend on the research, and then enter the other tasks below the first one and representative bars at the points in time when you expect to undertake them. The bar spans may overlap, as, for example, you may conduct research and choose software during the same time span. As the project progresses, secondary bars, arrowheads, or darkened bars may be added to indicate completed tasks, or the portions of tasks that have been completed. A vertical line is used to represent the report date.
The S Curve is a well known project management tool and it consists in "a display of cumulative costs, labor hours or other quantities plotted against time”. The name derives from the S-like shape of the curve, flatter at the beginning and end and steeper in the middle, because this is the way most of the projects look like.
Work Breakdown Structure- (WBS) A division of a project into tasks and substasks. The tasks are numbered to indicate their relationship to each other. WBSs are indispensible for project planning, particularly when estimating time and resource requirements. Some industries use established work breakdown structure systems for billing and reporting purposes.