INTRODUCTION TO NETWORK ANALYSIS

Network Analysis or Critical Path Analysis (CPA) or the American “Program, Evaluation and Review Technique” (PERT) is one of the classic methods of planning and controlling the progress of projects.

A method of analysis aimed to schedule a set of tasks so that they are all completed in the shortest possible overall time. The difficulty is that the various tasks take different lengths of time to complete and that each task cannot be started until certain prerequisite other tasks have been completed

PROCEDURES FOR CPA(CRITICAL PATH ANALYSIS) OR NETWORK ANALYSIS

Step One: List the Major Activities

The procedure begins by listing all the known or expected major activities to be undertaken in planning and managing a research or other type of project. The level of detail or finiteness of the activities will depend on your determination of their importance or "criticalness" to completing your project planning and management according to various time constraints. Over time in using CPA, whether by hand or by computer, you will "learn" how detailed you need to be for success in using the technique as a time management tool.

Step Two: Sequence the Major Activities

The next step is to sequence each activity into a logical order based on when it must or is most likely to occur. The sequence you select will be peculiar to your research or planning project, but certain activities logically precede others (for example, in planning some type of meeting formulating objectives almost always takes place before you obtain the meeting speakers). This step usually requires some reshuffling of activities before the final sequence is determined. Experience with planning and the CPA technique will facilitate this sequencing step.

Step Three: Construct an Activity Flow Diagram

In the third step you construct a schematic or flow diagram detailing the sequence of activities determined for an overall planning effort or research project. This step requires an understanding of three basic definitions:

• Event - the start or completion point of a meeting task or activity. Events do not consume time or resources but are used as notations in constructing a CPA network.
• Activity - the performance of an actual meeting task or activity. Activities do consume time and/or resources.
• Network - the flow diagram constructed by connecting events; this details the sequence of activities for a particular meeting.

Step Four: Estimating the Time for an Activity

·         The next step involves estimating the time required to perform each activity. Time is usually represented on most networks in days or in weeks. In the CPA process it is recommended you estimate the time required for each activity utilizing as guides such criteria as experience, suggested time requirements made by colleagues or  planning authorities, and known limitations of staff, resources, and money. A thoroughly constructed network might even have defined how many people and who will be working on a given calendar day, although there will be occasions when approximations will be just as useful.

Step Five: Computing the Expected Times to Complete All Activities
Following an estimation or determination of the time required for each activity, the planner needs to calculate totals or the earliest possible time that each event can be reached. Symbolized on Figure 3 by the letter "T," this total is derived by summing the estimated times of all activity paths leading to any particular event.