According to the PMBOK Guide, group decision-making techniques are used to reach a conclusion when multiple alternatives or requirements are being evaluated. These are primarily utilized in the Collect Requirements and Validate Scope processes.
* Plurality: This is a decision-making technique where a decision is reached by the largest block in a group, even if a majority is not achieved. For example, if there are three options and the votes are split
$40\%$, $35\%$, and $25\%$, the option with $40\%$ wins.
* Other Group Decision-Making Techniques:
* Unanimity: Everyone agrees on a single course of action.
* Majority: Support from more than $50\%$ of the members of the group.
* Dictatorship: One individual makes the decision for the entire group.
Analysis of Other Options:
* A. Brainstorming: This is a Data Gathering technique used to identify a list of ideas in a short period of time. It is used to generate options, not to decide which option to pursue.
* B. Focus groups: This is also a Data Gathering technique. It brings together prequalified stakeholders and subject matter experts to learn about their expectations and attitudes about a proposed product or service.
* C. Affinity diagram: This is a Data Representation technique. It allows large numbers of ideas to be classified into groups for review and analysis. It organizes ideas but does not function as a decision- making mechanism.