Gantt charts, along with Work Breakdown Structure (WBS), earned value performance measurement (EVPM), and the precedence diagram method (PDM), make up the big four of project management. WBS identifies activities that you need to accomplish, a Gantt chart or PDM network schedules these activities and earned value evaluates performance and communicates progress.
A Gantt chart may be the most popular tool associated with project management. It is a timeline chart. A Gantt chart defines start times and durations for each project task. Also, it portrays how tasks are positioned by showing how they occur simultaneously, sequentially, and separately.
An Overview of Gantt Charts
Gantt charts are valued as a way to quickly and clearly communicate your project’s schedule and progress.
As a core project management tool, a Gantt chart provides a graphical illustration of a schedule that helps you plan, coordinate and control tasks for your project. Gantt charts are traditional management aids used to schedule projects. They may be simple schedules that you develop on graph paper or complex and sophisticated versions that you create with computer software.
Think of a Gantt chart as a matrix that contains project work. Horizontal bars represent planned start and finish dates for each activity.
The purpose of a Gantt chart is to organize and clarify planned use of resources and occurrence of activities in a time-oriented framework.
The Mechanics of a Gantt chart
The overriding intent of a Gantt chart is to organize and clarify that actual of planned use of resources by creating horizontal bars to represent activities and exercising control against the bars.
Gantt charts use forward scheduling logic. Use forward scheduling by setting today’s date as Day Zero and making time estimates for each activity. Forward scheduling provide you with an opportunity to create trial-and-error schedules. This supplies you with ideas of what different arrangements of tasks may involve. Once you have an acceptable arrangement, identify relationships for all activities and construct and extend each bar into the future.
Use progress bars to exercise control.
Project Milestones
Milestones are important checkpoints. They are typically part of your project’s critical path. They represent important events to include on your Gantt chart that are not tasks. More correctly, milestones signify zero-duration stages of your project. When milestone dates are not met, your entire project schedule suffers.
It is possible (probable) that milestones change as your project progresses.
Gantt Chart Construction
When you construct a Gantt chart, use a common format. Some flexibility is permissible under special circumstances.
To get started, make sure to use a WBS to identify all activities or work packages that you need to accomplish to make your project successful. Remember, a WBS does not sequence events. Sequencing tasks is the job for a Gantt chart.
Follow these steps:
- Identify project activities, in order of their occurrence, on the left side of your project form.
- Develop estimates for each activity.
- Create time buckets across the top of your page that represent the appropriate period of time.
- For each activity, indicate start and finish times by creating task bars and by filling in/highlighting across each row.
- Assign a milestone.
- Share your Gantt chart with all key stakeholders (including your project team).
- Monitor your project and create progress bars.
- Gantt charts do not easily reveal a project’s critical path.
- Gantt charts do not clearly identify a behind schedule condition.
- Gantt charts present a challenge for recording progress.
- There are no widely accepted standards for Gantt charts.
- Gantt charts require a great deal of updating and posting.
- Gantt charts are difficult to use to respond to customer requests for accelerated project delivery.