Network Analysis

Network Analysis

Network Analysis is a core technique available to the Project Managers for planning and controlling their projects. It has wide application in the architectural projects, transportations projects etc. Network analysis is a mathematical model of analysing complex problems, as in transportation or project scheduling, by representing the problem as a network of lines and nodes. It can also be described as an analytic technique used during project planning to determine the sequence of activities and their interrelationship within the network of activities that will be required by the project. It involves breaking down a complex project’s data into its component parts (activities, events, durations, etc) and plotting them to show their interdependencies and interrelationships. In real-life scenario, it can be used as a data processing method using topologically linked data such as street maps or river networks with the purpose of determining the routes between geographic locations, and other analyses requiring the consideration of path and direction.

Following are the well-known methods for Network Analysis in project management:-

·         PERT

The military developed the Program Evaluation and Review Technique (PERT) in the 1950s for projects involving hundreds of contractors. In PERT you analyse the network by calculating three timelines for each task in the network: the shortest possible time, the longest possible time and the most likely time. Combining these via a mathematical formula (see resources) gives you the expected time for each activity. This approach works well for projects where setting exact timelines for different tasks is impractical. Generally PERT used for entirely new product, when nobody have an idea about the development span.

·         CPM

DuPont developed a Critical Path Method (CPM) designed to address the challenge of shutting down chemical plants for maintenance and then restarting the plants once the maintenance had been completed.

Complex project, like the above example, require a series of activities, some of which must be performed sequentially and others that can be performed in parallel with other activities. CPM models the activities and events of a project as a network. Activities are shown as nodes on the network and events that signify the beginning or ending of activities are shown as arcs or lines between the nodes. In CPM, you analyse the network diagram to identify the chain of dependencies -- tasks that have to be done in sequence -- that consumes the most time.

·         Event Chain Methodology

Event chain methodology considers unexpected problems that can disrupt your network. After creating the diagram and diagnosing the critical path, you draw up a list of events and chains of events -- a natural disaster shutting you down, for example -- that might delay the critical tasks and extend the project timeline. Once the events are identified, use statistics to calculate the risk of a delay and determine which events require preparation.

·         Gantt Charts

Once a project is under way, Gantt charts provide a quick display of the status of each task in the project network. The chart uses a calendar or a spread sheet to display the anticipated timeline for each task and the current progress. If your critical path requires one of the tasks be half-completed by March and it's only 20 percent along, that's a clear sign of problems. Even project managers employing CPM or PERT use Gantt charts for a quick reference tool. Gantt Charts are mostly liked by senior management to grasp the overall project progress.