Bar chart advantages and limitations

A bar chart (Gantt chart) is a graphical schedule in which activities are listed down the left side and time is shown across the top; each activity is a horizontal bar whose start, length and end show its start date, duration and finish date.

Activity   W1 W2 W3 W4 W5 W6 W7 W8
Survey     ####
Design        ######
Procure             ####
Build                  ##########
Test                            ####

Progress is shown by shading the completed part of each bar and a vertical "today" line.

Advantages

• Simple to prepare, read and understand, even for non-technical people.
• Shows the schedule and progress at a glance.
• Good for communication, reporting and small projects.
• Easily used for resource and cash-flow planning below the chart.
• Low cost; needs little training.

Limitations

• Does not show the dependency (logical relation) between activities clearly.
• Does not show the critical path or float, so priorities are unclear.
• Hard to update when changes occur; poor for large, complex projects.
• Gives no probability or uncertainty of time.
• Not suitable for trade-off analysis of time and cost.
• Result depends on the planner's judgement.