The 'Act' phase of the PDCA cycle is centered on continual improvement and taking corrective actions based on the results of the 'Check' phase. This phase ensures the Business Continuity Management System (BCMS) remains effective, adequate, and suitable over time. A critical component of this is communicating the improvements, changes, and outcomes of corrective actions to key stakeholders. This communication closes the feedback loop, demonstrates responsiveness to stakeholder needs and performance data, and thereby actively maintains the integrity of the BCMS and the engagement of stakeholders.

A. Plan: This phase establishes the initial framework, including identifying stakeholders and defining the communication strategy, but it does not encompass the ongoing, active maintenance of communication.

B. Do: This phase involves the operational execution of the BCMS, including carrying out planned communications during exercises or incidents, rather than the strategic maintenance of the system through improvement.

C. Check: This phase focuses on monitoring and reviewing the BCMS's performance, which includes gathering feedback from stakeholders, but it is the subsequent 'Act' phase that responds and communicates the resulting actions.

1. ISO 22301:2019, Security and resilience — Business continuity management systems — Requirements.

Section 10.2 (Continual improvement): This clause, corresponding to the 'Act' phase, states, "The organization shall continually improve the suitability, adequacy and effectiveness of the BCMS." This process of improvement inherently requires communication with stakeholders to report on progress and changes, thus maintaining the system's relevance and stakeholder confidence. The 'Act' phase is where the system is actively sustained.

2. Moeller, R. R. (2017). Executive's Guide to COSO Internal Controls: Understanding and Implementing the New Framework. John Wiley & Sons.

Chapter 4, The COSO Internal Control Framework, PDCA Cycle: While discussing management systems broadly, the text explains that the 'Act' phase involves management taking action to improve processes based on what was learned in the 'Check' phase. This action includes communicating changes and improvements to ensure the system is maintained and stakeholder expectations are managed.

3. Zairi, M. (1997). Business process management: a boundaryless approach to modern competitiveness. Business Process Management Journal, 3(1), 64-80. https://doi.org/10.1108/14637159710161585

This academic paper discusses the PDCA cycle in the context of business process management. It emphasizes that the 'Act' stage is not just about implementing changes but also about standardizing improvements and communicating them throughout the organization and to relevant parties to sustain the gains, which aligns with the concept of "maintaining communication."