When there are changes in the project requirements, such as changes in the government's cybersecurity requirements, it is important to manage these changes through a formal change control process1. This process usually involves documenting the change, estimating the effort required to implement the change, modifying the project schedule to include the change, and getting approval from the customer or project sponsor1. In this case, since the design changes can be made at no additional cost, the project manager should direct the team to request a change through the change control process to manage the new cybersecurity requirements1.
References: How to Manage Project Changes and Stay Ahead of the Curve

Three-point estimating is a technique that can be particularly useful when there is uncertainty about the individual task estimates. It involves the development team providing optimistic, pessimistic, and most likely estimates for each task, which can then be used to calculate an expected duration for the entire project. This method is beneficial when the team lacks experience with similar projects, as it allows for a range of possible outcomes to be considered, which can lead to a more realistic and reliable estimate123.
References:
Expert-Guided Software Project Estimation Techniques1
Software Development Estimation: A Quick Guide - ProjectManager2
Five keys to estimating - Project Management Institute3

According to the PMBOK Guide, the communications management plan is a component of the project management plan that describes how project communications will be planned, structured, implemented, and monitored for effectiveness. It also defines the communication methods, formats, frequency, and escalation process for different types of communication. In this scenario, the project manager should update the communications management plan to include informal requests from the executive, such as the dashboard, and specify how they will be handled by the project team. This way, the project manager can ensure that the communication expectations of the executive are met, and the project team is aware of their roles and responsibilities in providing the requested information. Updating the stakeholder engagement assessment matrix, asking the team member to develop a dashboard, or telling the team member to route the request through the project manager are not effective options, as they do not address the root cause of the communication issue, which is the lack of a clear and comprehensive communications management plan. References: PMBOK Guide, 7th edition, pages 123-124, 127-128.

To prevent the situation where the security team declined the deployment to the production environment, the project manager should have reviewed the compliance requirements with stakeholders. Here's why:
1.Compliance Requirements: Compliance requirements are essential for any project, especially in government- owned companies. These requirements ensure that the project adheres to legal, regulatory, and security standards. By reviewing compliance requirements early in the project, the project manager can identify any potential gaps or issues related to security.
2.Stakeholder Alignment: Engaging stakeholders, including the security team, during the planning phase allows the project manager to understand their expectations and concerns. It also provides an opportunity to address security-related matters proactively.
3.Risk Assessment: By reviewing compliance requirements, the project manager can assess potential risks related to security and take necessary actions. This includes implementing security measures, conducting vulnerability assessments, and ensuring that the project aligns with organizational security policies.
4.Iterative Approach: The iterative approach used in this project allows for incremental development and testing. However, security considerations should be part of each iteration. By involving stakeholders early and continuously, the project manager can address security concerns throughout the development process.
5.Communication: Regular communication with stakeholders ensures that everyone is on the same page regarding security expectations. It also helps in identifying any changes or updates to compliance requirements during the project lifecycle.
In summary, reviewing compliance requirements with stakeholders and addressing security concerns throughout the iterative process would have helped prevent the security team's decline during deployment to the production environment.
References:
*PMI, PMBOK Guide, 6th Edition, p. 357
*PMI, PMP Certification Exam Outline, p. 9
*Additional Reference: Asana - Understanding the Iterative Process
*Additional Reference: Monday.com - How to Use an Iterative Process for Projects
*Additional Reference: Asana - Understanding the Iterative Process
*Additional Reference: Monday.com - How to Use an Iterative Process for Projects

In a situation where the original vehicle supplier cannot deliver as agreed, the project manager should first review the existing service contracts for any clauses or options that could facilitate the procurement of the vehicles. This action is in line with the best practices of procurement management, which suggest exploring all contractual avenues and existing relationships before seeking external solutions2. It also adheres to the principles of change management, ensuring that any alterations to the project plan are made within the framework of established agreements and with proper oversight3. References: = Exam PMP topic 1 question
214 discussion - ExamTopics, Contract/Procurement Management | PMI, Procurement Management Overview | Project Management Professional (PMP).