Page 2 - OPERATIONS RESEARCH

NETWORK SCHEDULING BY PERT/CPM

Network Scheduling is a technique used for planning and scheduling large projects in

the fields o construction, maintenance, fabrication, purchasing, computer system installation,
research and development designs, etc.

There are two basic planning and control techniques that utilize to complete a pre-
determined project or schedule. These are: PROGRAM EVALUATION AND REVIEW

TECHNIQUE (PERT) and CRITICAL PATH METHOD (CPM).

NETWORK: BASIC COMPONENTS

A Network is a graphic representation of a project’s operations and is composed of activities and
events that must be completed to reach the end objective of a project, showing the planning

sequence of their accomplishments, their dependence and inter-relationships.

ACTIVITY: An Activity is a task, or item of work to be done, that consumes time, effort,
money or other resources.

EVENT: An Event represent the start (beginning) or completion (end) of some activity and s

such it consumes no time. It has no time duration and does not consume any resources. An event
is called a NODE. An event represents the joint completion of more than one activity is called

MERGE EVENT. If it represents the joint initiation of more than one activity, it is called a
BURST EVENT.

Activities can be further classified into the following three categories:

PREDECCESSSOR ACTIVITY: An activity which must be completed before one or

more other activities start is known as predecessor activity.
SUCCESSOR ACTIVITY: An activity which started immediately after one or more of

other activities are completed is known as successor activity.