A schedule is essentially a timeline showing the timing, sequence, durations, dependencies and constraints of the activities and events for a project. The schedule can be presented in a calendar format or on a time-phased graphic. An example of the latter is the Gantt chart, an extremely effective communication and management tool because of its ubiquitous use in the business world. Gantt charts are ideally suited for identifying and tracking tasks along the critical path, identifying "float" in a task, performing "what if" analyses in the event of delays in the schedule, and for facilitating the management of resources for each task.
A basic Gantt chart lists the names of the project tasks and the starting and ending dates for each task in adjacent columns in a spreadsheet format. A graphical display of each task, its duration, and its relationship to preceding and succeeding tasks is shown in an adjacent horizontal bar chart with a timescale on the x-axis. The basic Gantt chart can be expanded to include resource information (names of individuals responsible for each tasks, their availability or budgeted hours).
Although Gantt charts can be created using spreadsheet or presentation graphics software, Gantt charts created using specialized software such as Microsoft Project® offer greater flexibility and ease of use. A Gantt chart created in Microsoft Project® allows changes to individual tasks to be made readily and easily and the results on the overall project timeline can be seen immediately.
5. The critical path consists of those tasks in a project schedule that must finish by their designated end dates in order for the entire project to finish on time. If an individual task along the critical path is delayed by one day, the entire project will be delayed by one day unless that day can be made up in another task also on the critical path.
6. Float is the difference between the time designated for completing a task on a schedule and the actual time expended to complete the task. Tasks that have zero floats are on the critical path