Estimate Activity Resources in PMBOK 6

In the process of defining activities, we determined which activities to perform throughout the project. Of course, the realization of these activities requires the use of a number of resources. These resources can be human resources or physical resources.

What is estimate activity resources process in pmp?

Estimate activity resources process in PMP is where we made some estimations about both the physical and human resources of each activity in the activity list according to assumptions and characteristics of activities.

In PMBOK 7 estimating is considered as a part of;

In which phase of a project would you estimate activity duration and resources?

Estimate the activity resources process is a part of;
In the lifespan of the project, this process is performed periodically when it is needed.

The estimate activity resources process is typically performed just after the sequence activities process and just before the estimate activity durations process. The main output of this process is resource requirements. Therefore after implementation of the estimate activity resources process, we will know what are the requirements to be able to complete predefined activities.

What are the outputs of the process?

Resource requirements: The main output of the process is resource requirements. In other words, resource requirements were the main objective to achieve before we start this process. 
Basis of estimates: As a result of estimation processes we eventually get an output. However, we have to support these estimations with additional data such as, how it was developed, what were the assumptions, constraints and confidence level. This is also an important output of the process.
Resource breakdown structure: It is a representation of categories and types of resources such as equipment, material, labor, etc.

What are the inputs to the estimate activity resources process?

  • Activity List and Activity Attributes: Since all of the defined activities of the project are listed in the activity list, it is a natural input to the process. From activity attributes input we can derive necessary information about the needed resources.
  • Scope Baseline: As scope baseline consists of scope statement, wbs and wbs dictionary, we can take requirements of the project from it.
  • Resource Management Plan: Like all other subsidiary plans, resource management plan provides guidance about the estimation process.
  • Assumption log: You have to take all assumptions and constraints of the project into consideration to make a proper estimation. So it is a natural input.
  • Resource Calendar: In order to estimate resources in the most approximate way, we need to have a resource calendar. From the resource calendar, we can extract information such as the type, quantity, competence, experience, and geographical location of the useful resource. In addition, the resource calendar contains information such as the time period when the resource is available. By using a resource calendar we may see possible holidays, the number of available resources, the competence of human resources and their main characteristics. Naturally, we need the list and characteristics of all project activities in order to decide which activity needs how many resources.

Which tools and techniques may be used to estimate activity resources?

  • Bottom-up estimating: It is the most convenient method to have estimates as realistic as possible for processes like estimate costs and estimate activity resources and durations. By starting from the smallest part of the work, making estimations by using more detail and aggregating them later will give a close estimate. However, it needs merit and time to do this. 
  • Analogous estimating: It is simply done by comparing the activities with similar projects that were previously performed.
  • Parametric estimating: Based on historical data and some project parameters, parametric estimation is done by following a specific algorithm.
  • Alternatives analysis: Sometimes an altenative analysis is necessary to choose which estimation or which method to use.
  • Project management information system (PMIS): There are many softwares and systems that are part of PMIS. These systems can be used to perform estimation process by using them.
  • Meetings: This is always a handy tool to use when it comes to estimation processes.
  • Expert judgment: Other project managers with former experiences, subject matter experts can share their judgments.