According to the PMBOK Guide, specifically within the Estimate Activity Resources process, labor (people), materials, equipment, and supplies are the primary examples of Resource Categories.
* Definition: Resource categories are high-level groupings of resources. Identifying these categories helps the project manager ensure that all necessary components for a task are accounted for beyond just human labor.
* The Difference between Category and Type:
* Resource Category: The broad group (e.g., Labor, Equipment, Material).
* Resource Type: The specific skill level or technical specification within that category (e.g., Senior Engineer, 5-ton Crane, Grade-A Steel).
* Resource Requirements: The output of this process is the Resource Requirements document, which identifies the quantity and type of resources required for each activity in a work package. This information is then used to build the Resource Breakdown Structure.
Comparison with Other Options:
* Resource Attributes (A): These are the specific characteristics associated with each resource, such as its location, availability, technical skills, or cost rate. They provide more detail than the category.
* Resource Types (B): As noted above, this is the level of detail within a category (e.g., " Electrician " is a type within the " Labor " category).
* Resource Breakdown Structures (D): The RBS is a hierarchical representation of resources by category and type. While labor and materials are found in an RBS, they themselves are the categories that form the structure.