Introduction to project network & Determination of critical path

Network Analysis

The network analysis is a method used to analyse, control and monitoring of business processes and workflows. Contrary to the work breakdown structure, a network diagram also considers the chronological order of activities, milestones and tasks, their durations and dependencies and visualizes them graphically or as a table, e.g. in a Gantt chart.

The network analysis enables project managers to take various factors into account when creating a project plan:

• Dependencies between activities
• Buffer times between activities
• Earliest and latest start and end dates
• Duration of activities
• Critical Path

Steps in Network Analysis

1. Network Design Requirements |Identifying Customer Design Requirements: As a network designer you need following steps to identify customer requirements:

Identify network applications and services that the organization wants to run in it network. Define the organizational goals. Define the possible organizational constraints and limitations, these limitations may be related to cost. Define the technical goals Define the possible technical constraints.

2. Describe the Existing Network-Characterizing the existing network is second step of the network design methodology. In this step, you need to identify a network’s existing infrastructure and services that are currently running. You can use the different tools to analyse existing network traffic, and tools for auditing and monitoring network traffic.
3. Designing the Network Topology and Solutions The best approach to design the network topology is the structure approach which allows you to develop the optimal solution with lower cost with fulfilling all requirements of customer like capacity, flexibility, functionality, performance, scalability and availability You can start the network designing process with information that you extract through:

Existing information and documentation Network audit Traffic analysis

4. Plan the network implementation In documentation you should have the step-by-step procedure of each aspect of modular network and have the complete detail for implementation of each step. Documentation must have rollback plan for each step, if something goes wrong you can back to previous step and after modification you can re-implement that step again
5. Construct a prototype network A prototype network is a subset of the full design, tested in an isolated environment. The prototype does not connect to the existing network. The benefit of using a prototype is that it allows testing of the network design before it is deployed before affecting a production network. When implementing a new technology such as IPsec, you might want to implement a prototype test before deploying it to the operational network.
6. Fully Document the Design Documenting the project is the best practice and has a number of advantages and future benefits.
7. Implement the Design In implementation phase network engineer implement the network’s designer design. In this phase network engineer implement the documented steps, network diagram into real network.
8. Verify, monitor and modify as needed Once your network is fully implemented then your job to run and operate the network properly, you have to monitor the network devices, traffic and other security aspects. You can make the modification if you find something wrong with network operation during monitoring of network. Also, if you need to add some more services and feature you can add these services too.

Determination of critical path

The Critical Path is the longest path of scheduled activities that must be met in order to execute a project.  This is important for Program Managers (PM) to know since any problems that occur on the critical path can prevent a project from moving forward and be delayed.  Earned Value Management (EVM) analysis focuses on the critical path and near critical paths to identify cost and schedule risks. Other schedule paths might have slack time in them to avoid delaying the entire project unlike the critical path. There might be multiple critical paths on a project.

The Critical Path is determined when analyze a projects schedule or network logic diagram and uses the Critical Path Method (CPM).  The CPM provides a graphical view of the project, predicts the time required for the project, and shows which activities are critical to maintain the schedule.

The seven (7) steps in the CPM are:

1. List of all activities required to complete the project (see Work Breakdown Structure (WBS)),
2. Determine the sequence of activities
3. Draw a network diagram
4. Determine the time that each activity will take to completion
5. Determine the dependencies between the activities
6. Determine the critical path
7. Update the network diagram as the project progresses

The CPM calculates the longest path of planned activities to the end of the project, and the earliest and latest that each activity can start and finish without making the project longer. This process determines which activities are “critical” (i.e., on the longest path) and which have “total float” (i.e., can be delayed without making the project longer).

The CPM is a project modeling technique developed in the late 1950s by Morgan R. Walker of DuPont and James E. Kelley, Jr. of Remington Rand.