Resource Calendar: Availability of Team Resources, Equipment, and Materials
PMBOK v8 Definition
A resource calendar is a calendar that identifies the working days and shifts during which each specific resource is available. It includes the start and end of normal business hours, weekends, and public holidays when each specific resource is available. Information on which resources (such as team resources, equipment, and materials) are potentially available during a planned activity period is used for estimating resource utilization. Resource calendars also specify when, and for how long, identified team and physical or virtual resources will be available during the project, at either the activity or project level.
This concept is central to the Resources performance domain, specifically within the Acquire Resources process (an output) and the Estimate Resources process (a key input for determining resource availability).
Why It Matters for the Exam
The resource calendar appears frequently in PMI exam questions testing your understanding of resource availability, utilization estimation, and schedule feasibility. Questions often present scenarios where a project manager must determine whether resources are available for specific activities, or ask you to identify which document contains availability information for team members, equipment, and materials. Expect situational questions where you must select the correct tool or output for managing resource constraints.
Key Points to Remember (for the exam)
- Definition: A resource calendar identifies working days and shifts when each specific resource (team, equipment, materials) is available.
- Content: Includes start/end of normal business hours, weekends, and public holidays for each resource.
- Purpose: Used for estimating resource utilization during a planned activity period.
- Scope: Can be at the activity level or project level.
- Main Process Output: The resource calendar is an output of the Acquire Resources process.
- Key Input: Resource availability information is essential for the Estimate Resources process.
- Common Confusion: Do not confuse the resource calendar with the project calendar—the resource calendar is specific to each resource, while the project calendar defines general working days for the project.
Typical PMI Exam Example
A project manager is planning the construction phase of a building project. She needs to know when specialized crane operators (team resources) and the crane itself (equipment) will be available during the next two months. Which document should she consult?
Answer: The resource calendar, which identifies working days, shifts, and availability periods for each specific resource (team resources, equipment, and materials).
PMI Exam Traps
- Trap: Confusing the resource calendar with the project schedule.
- Reality: The resource calendar shows when resources are available; the project schedule shows when activities are planned.
- Trap: Thinking the resource calendar only applies to team resources.
- Reality: The resource calendar applies to team resources, equipment, and materials—all physical and virtual resources.
- Trap: Assuming the resource calendar is created once at the start of the project.
- Reality: The Acquire Resources process is performed periodically throughout the project as needed, and resource calendars are updated accordingly.
- Trap: Confusing the resource calendar with the Resource Breakdown Structure (RBS).
- Reality: The RBS categorizes resources by type (role, material, equipment, level, grade); the resource calendar shows timing of availability for each specific resource.
Important PMI Connections
| Related Concept | Relationship Type | Exam Attention Point |
|---|---|---|
| Estimate Resources process | Input | Resource calendar provides availability data for estimating type, quantity, and characteristics of resources needed |
| Acquire Resources process | Output | Resource calendar is produced after obtaining team and physical resources |
| Resource Breakdown Structure (RBS) | Complementary | RBS categorizes resources; resource calendar schedules their availability |
| Project schedule | Input/Output relationship | Resource calendar constrains activity scheduling; schedule updates may trigger resource calendar updates |
Quick Review Questions
- What information does a resource calendar include regarding team resources, equipment, and materials?
- In which process is the resource calendar produced as an output?
- How does the resource calendar support the Estimate Resources process?
- What is the difference between a resource calendar at the activity level versus the project level?
- Why must the Acquire Resources process be performed periodically throughout the project?
PMBOK v8 Reference
Section 2.6.2.2 – Estimate Resources (Resources performance domain)
Section 2.6.2.3 – Acquire Resources (Resources performance domain)
Figure 2-43 – Acquire Resources Inputs, Tools and Techniques, and Outputs