What is time in a project?

Traditionally project time is the duration between the project start and the project end, sometimes known as the overall project duration. Within the project duration there are a series of activities that may or may not have logical dependencies. Scheduling allows an estimate of time for each of the individual activities. By taking into consideration the project context, the project requirements, available resources and budgets, a critical path (single or multiple) of activities through the project can be determined. This critical path represents the sequence of activities through a project network from the project start time to the project end time, the sum of whose durations determines the overall project time. If this critical path exceeds the time allowed to complete the project, then the project needs to be re-planned, such as adding additional resources, subcontracting out work, conducting up front de-risk work or taking advantage of opportunities that may arise after the start of the project.