Resource Histogram
A time-phased bar chart that displays the planned workload for a resource across consecutive periods (such as days, weeks, or months).
Key Points
- Visualizes resource utilization over time using bars for each time period.
- Bars typically represent planned hours or effort for a single resource, role, or team.
- Helps identify over-allocation or underutilization compared to available capacity.
- Supports resource leveling and forecasting by linking directly to schedule assignments.
Example
A project manager generates a weekly resource histogram for the next two months. It shows Backend Developer A at 56 hours for Week 3, exceeding the 40-hour capacity. The PM reassigns two tasks to another developer, reducing Week 3 to 38 hours and balancing the workload without impacting the critical path.
PMP Example Question
Which tool best shows, by time period, how many hours each team member is planned to work so the project manager can spot over-allocation?
- Resource calendar
- Resource histogram
- RACI chart
- Pareto chart
Correct Answer: B - Resource histogram
Explanation: A resource histogram is a bar chart that displays planned workload across time, allowing the PM to see over- and under-allocation. A resource calendar shows availability, not time-phased workload; RACI shows responsibilities; a Pareto chart ranks causes by frequency.