Network planning.

What is and how does network planning and management work? It is a system that solves problems of planning, management and development of large complexes in the national economy, scientific research, technological and design preparation for the production of new varieties of products, reconstruction of old and construction of new facilities, and major repairs of fixed assets using network schedules.

Network planning allows you to establish the exact relationship between the work that is planned and the results that can be achieved through the performance of these works. It also provides an opportunity to promptly calculate and adjust the plan of any works. Network planning - the basis for the use of electronic computers in production management and the creation of automatic control systems. This technology allows to release a large human resource, engaged in drawing up standard plans for more creative work.

Network planning methods consist in creating a logical mathematical model of an object that is controlled in the form of a network model or a graph in the memory of an electronic computer and reflecting the duration and interrelationships of all processes occurring during the execution of this set of work.

The network schedule is first optimized by means of computer facilities and applied mathematics, and then used for the purpose of operational management and organization of work. The schedule reflects events and works. An event characterizes either the beginning or the completion of a certain work, and the work itself expresses an action, the fulfillment of which is necessary for the transition from an event that precedes it to the next. On the graph, events are represented in the form of circles, and work, in the form of arrows, which demonstrate the relationship between events (the reverse version of the image is also possible: the work is by circles, and the events connecting them are arrows).

Network planning requires a specific, clear description of the work, indicating the performer of each of them, indicating the time, which is measured by days, weeks, decades, months, and is placed above the arrow. Temporary assessments are made there by responsible executors of the relevant work. All the work that is done on the schedule, ultimately lead to the planning. Network planning of work duration requires the use not only of normative documentation, but also confirming its experimental data.

But often it happens, especially in cases when the development of new types of products is being conducted, that the time of execution can not be expressed with the help of a single reliable figure. In such cases, the performer must give three estimates:

1) Optimistic evaluation. The minimum duration of work, possible in the most favorable conditions, in the event that no one and nothing prevents its implementation.

2) Pessimistic assessment. The maximum time that can be required for the performance of work, in the event of difficulties.

3) The most probable estimate. Shows the time that will be spent under normal operating conditions.

One of the most important elements in plotting is the length of the paths. Ways are divided into full and critical. The full path is a line whose beginning is the initial event of the network, and the end is its final event. Critical path - the longest, characterizes the duration of the execution of all the works of the project, that is, the time that will be spent on achieving the ultimate goal.

The critical path is the most important indicator in the entire network management system and is the basis for choosing the most appropriate plan and for monitoring the progress of work.