Explanation
An onion diagram is a technique that helps to identify and analyze the stakeholders involved in a project or a solution. It consists of a series of concentric circles that represent different levels of stakeholder influence and interest. The innermost circle contains the core stakeholders who have the highest influence and interest, such as the project team and the sponsor. The outermost circle contains the peripheral stakeholders who have the lowest influence and interest, such as the regulators and the competitors. The circles in between contain the primary and secondary stakeholders who have varying degrees of influence and interest, such as the customers, the suppliers, the partners, etc. An onion diagram helps to ensure that everyone who needed to be included has been considered and engaged appropriately.
References:
[BABOK Guide v3], Section 2.2: Identify Stakeholders, p. 16-17
CBAP / CCBA Certified Business Analysis Study Guide, 2nd Edition, Chapter 2: Business Analysis Planning and Monitoring, p. 48-49 Certified Business Analysis Professional (CBAP) Specialization, Course 1: Business Analysis:
Planning and Monitoring, Week 2: Plan Business Analysis Governance, Video: Stakeholder Identification Techniques Onion Diagram - Stakeholder Mapping, Blog Post, June 2018