A brief explanation of how to develop network diagrams to make a correct control in organizations, activities or projects.
In companies, activities must be carried out in a predetermined order, and network diagrams facilitate the representation of priority relationships, with logical and sequential sequences. To obtain an adequate network diagram, we must have activities that can be easily identified, that have a beginning and an end, that are related to each other and with a specific time to be carried out
Any network or diagram allows permanent control of the progress of works, objectives and goals, according to the anticipated schedules, also pointing out the shortest way of execution without sacrificing quality (similar to the concept of optimal pareto.
Network: It is a combination of events that logically describe the execution of business projects or activities.
Elements of a network:
Event: It signals the beginning and end of the task or action, it does not consume time or resources.
- It is represented by a node or a circle.
Activity: It consists of a set of tasks, which must be carried out, to carry out a work; it consumes time, has a beginning and an end, requires labor, raw materials and other resources.
- It is represented by an arrow, the direction of which indicates the sequence.
Fictional activity: It is one that does not consume time or work. It is represented by broken lines and serves to save the logic of the network.
Critical Path: It is the longest path through the network and represents the shortest possible time for the execution of the project.
Figure 1: Basic parts of diagramming
Images
The circles represent the start or end of a task or action.
The arrow indicates the sequence and tempo.
Activities or events must be duly numbered or identified within an adequate sequence.
For example, if we are building a building, it is logical that the land purchase process has a 1 and the base construction phase has a two and so on with all the stages to develop the activity.
The shape of the network will depend on the level of activities, if all the elements are done at the same time, it will have a more vertical shape if it is sequential it will be horizontal.
The time consumed by an activity can be of three types:
- Optimistic time: It is the shortest time in which an activity can be executed Pessimistic time: The worst possible situation (without representing the end of the project) Probable time: Exact possible time, an estimated time can be obtained through the following relationship:
where: a = optimistic time, b = pessimistic time m = most probable time te = estimated time.
Example of a small final diagram
Figure 2: Small Diagram:
This diagram implies several things:
- Event 5 cannot be fulfilled without the fulfillment of 2 3 and 4.2 and 4 happen in the same stage. 3 is smaller or simpler. Time used between 1 and 3 is less than between 3 and 5.
If the time forecasts were made, the lines would carry the estimated activity times of each action.
The diagramming of events and phases is a very useful control and planning instrument. Every manager should use these simple procedures to improve the control of the actions to be carried out.
Taken from: Design and development of investment projects: Econ: Bolivar Costales Gavilanes, Escuela Politécnica del Ejército. Ecuador 1996.
