To develop a preliminary network schedule, you first need to define the activities, sequence them in the right order, estimate the resources required, and estimate the time it will take to complete the tasks. The activity definition process is a further breakdown of the work package elements of the WBS. It documents the specific activities needed to fulfil the deliverables detailed in the WBS. These activities are not the deliverables themselves but the individual units of work that must be completed to accomplish the deliverables. Activity definition uses everything we already know about the project to divide the work into activities that can be estimated. Scheduling aims to predict the future, and it must consider many uncertainties and assumptions. A variety of inputs and tools are used in the scheduling process, all of which are designed to help you understand your resources, your constraints, and your risks. The result is a plan that links events in the best way to complete the project efficiently.

Once you have outlined the primary schedule, you need to review it to make sure that the timing for each activity is aligned with the necessary resources. Below are some commonly used tools to achieve this:

What if “scenario analysis – This method compares and measures the effects of different scenarios on a project. You use simulations to determine the impact of various adverse, or harmful, assumptions – such as resources not being available on time, or delays in other areas of the project. You can then measure and plan for the risks posed in these scenarios.

Resource levelling – Here, you rearrange the sequence of activities to address the possibility of unavailable resources and to make sure that excessive demand is not put on resources at any point in time. If funds are available only in limited quantities, then you change the timing of activities so that the most critical activities have enough resources.

Critical chain method – This also addresses resource availability. You plan activities using their latest possible start and finish dates. This adds extra time between events, which you can then use to manage work disruptions.

Risk multipliers – Risk is inevitable, so you need to prepare for its impact. Adding extra time to high-risk activities is one strategy. Another is to add a time multiplier to specific tasks or certain resources to offset overly optimistic time estimation.

A Schedule Network Analysis is a graphical representation of a schedule showing each sequenced activity and the time it takes to finish each one. It’s used to identify early and late start dates, as well as early and late finish dates, for the uncompleted portions of project schedule activities. This analysis also helps determine the Critical Path, What-if Analysis, and Schedule Compression. It’s usually represented in the form of a Gantt chart or PERT Chart.

Schedule Network Analysis and diagrams are extremely useful for projects in many ways and provide many benefits such as;

·         Activity sequencing

·         Project length

·         Completion date

·         Critical Path

·         Lead and Lag times

·         Graphical representation of the entire project

·         Possible slippage

·         Possible what-if analysis

·         Possible schedule crashing analysis

Drawing the project network places, the activities in the right sequence for computing start and finish times of activities. Activity time estimates are taken from the task times in the work package and added to the network. The below diagrams shows an example of activities and the time lines associated with these tasks and how there are predecessors to some of these tasks.

In projects, float or slack is the amount of time that a task in a project network can be delayed without causing a delay to: subsequent tasks ("free float") project completion date ("total float"). Slack helps project managers run projects efficiently without compromising quality and the network diagram outlines these tasks and predecessors.