The preparation of logic diagram can be divided into three stages:

a.     Developing logic diagram for each work package

b.     Intergrating work packages

c.     Transforming integrated work package logic diagram into a project logic diagram.

In practice, work-packages are considered in the sequence they occur. Further the drawing of work-package logic diagrams and the process of integration can be carried out simultaneously.

Developing work-package logic diagram

The activity-dependence table provides the necessary data for developing the work-package logic arrow diagram.
Logic diagrams can be developed for each work-package. These diagrams based on the logic, given in the activity-dependence table for each work package of the pumping station sub-project are shown in fig.







Integration of work-package logic diagrams

The term integration implies the connecting of logic diagrams of the work packages into a single-project logic diagram.
Prior to the commencement of integration, it is essential that, as far as possible, the paper on which the project logic diagram is to be drawn, is divided into various strata. The term straftification means a division of the diagram in such a way that activities pertaining to the same department, contract, site location or method of construction can be suitably grouped by drawing horizontal and/or vertical imaginary lines. Generally, the integration link can be visualized from the work-breakdown structure.
The process of integration of work-package logic diagram is commenced from the beginning of the project, and work packages falling in the same strata are connected in the sequence of their occurrence. While integrating, the sequence of activities terminating into and emerging out and the connecting key events must be verified by questioning each about its preceding and succeeding activity.
Broadly, the integration of work-package of the pumping station sub-project can be divided into two strata, namely, civil works and mechanical works. The key events can be positioned as shown in fig.



While integrating the work-package diagrams, the logic of all the activities should be re-examined to find their interdependence. This interdependence can initially be correlated with dummy activities. In some cases, the activities may have to be re-drawn to conform to a given logic.
The sub-project logic diagram, derived after integrating the work-package logic diagrams of civil and mechanical works of the pumping station sub-project, is shown in fig.

The main points to be noted are as follows:

a.     The start event is common to both civil and mechanical works logic diagram.

b.    The erection of gantry is to start with completion of roofing. A dummy activity has been interposed to maintain this logic.

c.     The commissioning of pumping set can commence after the electric lines have been laid inside the building. This is shown by a dummy activity.

d.     It is desirable to complete the plumbing and sanitary works and commission the pumping set prior to the laying of floor, so as to avoid breaking floor surface in case of defects. A dummy, connecting circle 3 and 4, has been used to show this logic.