General Description of Program Management

The simplest program management tool was developed by Henry Gantt and bears his name. Gantt Charts plot the steps necessary to complete a project against a timeline. Each task or activityis plotted by a bar or line which begins at a definite time and ends at a defined time. The activity bars are arranged in ascending or descending sequence of time (i.e., in the order in which the tasks begin or the order in which they end). The Gantt Chart provides milestones, or markers, for assuring that a program is on track.

While Gantt Charts have the advantage of simplicity, and do perform the work of determining the tasks and some of the order in which they are to be performed, they can hide as much as they display. The linkages between the various tasks are not made explicit nor is the relationship between resources and the time to complete a task. While Gantt Charts can tell a manager whether a program is on track, they often cannot provide information about how to get it back on track.

Enter PERT--Program Evaluation and Review Technique (Krueckeberg & Silvers, 1974). PERT was first used the 1950s on projects like the construction of the Polaris submarine-a project which required coordinating the activities of 250 contractors and 9000 subcontracts. Like Gantt charts, PERT requires task definition and duration; in addition, PERT requires specification of the relationship between tasks and the resources required to complete each task in a given period of time. Once the network of activities is determined, CPM (Critical Path Method) is used to reallocate resources to find the shortest time in which the project can be completed (and what resources would be needed to do that).

Take a simple example: Suppose you plan to build an addition on your house. First, you have to decide what you are going to do. For this example, you might have to build a foundation, frame the addition, do the electrical work, sheetrock and trim, roofing, landscaping, exterior painting, and interior painting/finishing. Then you'd have to decide in what order things have to be done. For example, you can't frame the addition until the foundation is done, and you can't put on the roof until the framing is done. On the other hand, once the framing is done the electrician can come in (but the sheetrock can't go up until after that, and the interior painting is last) and the exterior painting and the landscaping can be done at the same time. Then you'd have to estimate how long it will take to do each task. The foundation could be dug, poured, and set in, say, two weeks-a week if you really pushed, three weeks if you get bad weather. Then you could add up the time it takes to do the various tasks to estimate how long it should take to complete the project. You could even shorten the time it took to complete the project if you sped up tasks that were holding back other tasks. This is, in effect, a Program Evaluation and Review Technique. In a "picture," one might draw something like this (by the way, this was done in Word using the “Drawing” function—Insert to Picture to AutoShapes, using Text boxes and arrows):

Exterior Paint

Now, suppose you want to get this addition built as quickly as possible. You could always "crash" the project, using CPM ("Critical Path Method"). The idea is to use estimates of time and cost to find the most efficient use of resources to get the job done. This means getting it done in the least possible time, neither wasting nor sparing costs. To do this, you might develop a table of time and cost information-for each task. What is the "normal" (expected) time the task should take, and what is the least ("crashed") time in which it could be done? And how much does it cost in each case for each task? Using these data, you could develop a "cost per week" for crashing (the crashed cost divided by the time saved). Using your PERT Chart, you could crash the cheapest activity path that is on the longest path for getting the job done (this is called the "critical path"). You could repeat this process, one path at a time, until all the paths have been crashed. Then you should ease up on all the "noncritical paths", just to the point that "all paths are critical"(i.e., so everything comes together at the same time-why spend more for crashing than you have to?).

In the example above, you might develop a table that looks something like this:

		Time		Cost
Path	Name	normal	crashed	normal	crashed
1-2	Foundation	2	1	$3000	$4000
2-3	Framing	4	1	$4000	$8000
3-4	Dummy
3-5	Electrical	.4	.2	$1000	$1500
4-5	Roofing	1	.4	$1000	$1750
5-6	Sheetrock	1	.4	$1000	$1500
6-7	Interior Finish	2	1	$1500	$3000
2-7	Landscaping	.4	.2	$500	$650
3-7	Exterior Paint	.8	.4	$600	$1000

Using this information, you would expect to complete the addition in 8 weeks at a cost of $12,600 . If you crashed the project, you could get it done in a little over 5 weeks, but it would cost an additional $5,750.

A simple project like this can be done fairly easily with paper in pencil. A larger project (like the Polaris submarine, for example), requires a computer program, such as Microsoft Project for Windows.

PERT

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