tions instantly, (2) the informatio

tions instantly, (2) the information could be restricted to the par¬ticular area of interest, and (3) the program could be updated from remote stations as new inputs occurred. Obviously, a program would need to be large and very involved to justify this kind of computer application.
There are many forms of network analysis. Some are simple, and others are complex; some are generalized, and others have been designed for specific types of projects. Variations of the net¬work analysis techniques are reviewed in the following para¬graphs.
A REVIEW OF NETWORK TECHNIQUES
Critical path scheduling is common to all network techniques. Networks are developed to represent a total project and to identify the specific tasks necessary to complete the program require¬ments. One path of the sequential work flow (out of the many possible paths) has the longest lead time and is, therefore, critical to the completion of the project.
Critical Path Method
One example of critical-path scheduling has been called critical path method, a technique which has been used by construction management for pWining, scheduling, estimating, and control¬ling engineering or construction projects. CPM was used by Du Pont in 1959 to schedule plant-maintenance shutdowns during changeovers. Subsequently, it was used to plan building con-struction and other iarge construction projects. -
The key tool in this technique of planning, scheduling, and controlling complex construction jobs is a diagram using arrows to represent specific jobs (Figure 9- 1). The diagram may be com-plex, as is evident from the example which illustrates the con¬struction requirements for building one floor of a multistory building. Therefore, it requires a comprehensive illustration to show all the required relationships of the project.
The important contribution of a line diagram showing all the key events or activities is that it clarifies the relationships of every task to every other task—something that the bar chart can-not do. In this way it also can show which jobs on a project are critical, those which can affect the completion of the project.
The diagram is the model which illustrates the jobs to be per¬formed to finish a project. The simplest form of diagram identifies