Hi @danag!

These three modules - Idea Management, Demand Management, and Continual Improvement Management (CIM) - work together to form an innovation-to-execution lifecycle in ServiceNow, but each has a distinct role.

Continual Improvement Management (CIM)

Definition: Is a structured framework to manage continuous improvements in services, processes, or performance.

Purpose: To ensure ongoing service excellence and value delivery via targeted improvement initiatives.

Stakeholders: Process Owners, Improvement Managers, Service Owners, Business Units

Evaluation: KPI impact, Strategic relevance, Feasibility and cost

Outcome: Improvements are tracked with clear phases, tasks, and performance metrics. 

Example: The ITSM team identifies an opportunity to reduce incident resolution time. A CIM initiative is created, split into phases (Plan :: Execute :: Validate), and tracked via dashboards.
Links:
Continual Improvement Management

Idea Management

Definition: A system for collecting, socialising, and evaluating ideas from users to drive innovation.

Purpose: To crowdsource ideas from employees, partners, or customers and evaluate them for business value and feasibility.

Stakeholders: Idea Submitters, Idea Managers, Business stakeholders

Evaluation: Number of votes, Strategic Fit, Feasibility

Outcome: High-value ideas can be converted into demands or improvement initiatives.

Example: An employee submits an idea to implement a chatbot for basic IT support. It garners votes and is approved by the Idea Manager. It is then promoted to a demand for further evaluation.

Links: Managing Idea Portal

Demand Management: 

Definition: A process to capture, evaluate, and prioritise business and IT demands aligned with strategic goals.

Purpose: To assess feasibility, impact, and cost of requests and manage them through approval and execution.

Stakeholders: Demand Managers, Business Relationship Managers, Executives

Evaluation: ROI, Strategic alignment, Resource capacity

Outcome: Approved demands are converted into projects, epics, or changes.

Example: A regional office submits a demand for a mobile field service app. It goes through assessment, gets scored high, and is converted into a project.

Links: Product Documentation | ServiceNow

Hope this helps! 
Please mark this as correct if it answers your question to help others in the future.