Page 8 - OPERATIONS RESEARCH

d. The arrow diagram of a network presented in part c can be represented as:

This events of the diagram are numbered such that their ascending order indicates the

direction of progress in the project.

CONCURRENT ACTIVITIES

This may be done in part allowing the subsequent activities to commence before the
preceding activity is fully completed. Such simultaneous or concurrent activities are to be

encountered in sewage work; for example trenching, laying pipe, welding pipe and back filling;
all going on simultaneously with suitable lags on construction work.

EXAMPLE:

A batch of four axles is to be processed on the following three machines in this sequence:
Lathe(L), Milling(M), Grinding(G).