Gantt Chart (Project Charts)
A Gantt Chart, or Project Chart, is used extensively by project managers and
other people involved in scheduling. While it is similar to a timeline in
that it deals with time and events, the format and purpose of a Gantt Chart
is very different. The Gantt Chart is a table with one task for each row
and time in the columns. The unit of time chosen depends on the length and
detail of the product, but some common units are weeks, quarters, months, and
years. Usually there is a column at the left listing the tasks, then columns
for start date, end date, and duration, followed by the columns for time.
Each task has a bar extending across the time columns, representing the duration
of the task. Milestones and critical path lines may also be used to add
further detail to the chart. Milestones are important checkpoints or deadlines
represented by small symbols in the time columns. Critical path lines connect
task bars to indicate a dependence of one task upon another's completion or
commencement.
Typical Uses
Gantt Charts are especially useful for organizing and maintaining the schedule of
a product. It also shows how certain tasks are dependent upon the completion or
commencement of others.
Best Practices
- Identify the purpose. First choose the process or project to be detailed on the Gantt chart.
- Create a timeline. Decide when the entire process will begin and when it must be completed. Now decide how to divide the increments of time for the duration of the project. Create a table with a column for each of the dates and increments you have decided to use and place them inside in chronological order.
- List tasks. Determine how many tasks there are in the process. Make a row for each and place the name of each task in its cell on the left side of the chart.
- Create progress bars. Now create a progress bar for each of the tasks. A progress bar is simply a horizontal bar that should be in line with the task name it represents and should begin beneath its start date and end beneath its end date (thus indicating the time at which the task will be in progress). Do this for each task. Some may overlap, meaning that they are occurring at the same time.
- Add critical paths. Use lines to connect a task to another if they are dependent on each other. If the completion of one task will trigger the beginning of another, draw a line from the end of the first to the beginning of the second with an arrow pointing to the second to show that it can begin after the first is finished.
- Add milestone markers. Choose a symbol to represent milestones, that is, major events that either have a large part in the process or must be completed before progress can continue. Place them on the chart beneath the date or time when they occur.
- Additional labeling. If there is anything else you wish to label you may do it now, whether you need to label who is in charge of each activity, or note the cost of each task. Fill in any information you find critical.
- Do not deviate. Use the Gantt Chart to maintain the schedule, and update it occasionally during the project.