Continuous Improvement is a major concept associated with Retrospectives. It pertains to the consistent effort to improve services, products, and processes over time. Within a PMI Agile setting, this typically applies to project processes and delivery. Retrospectives offer a dedicated moment for the team to reflect on the most recent project or sprint, and identify areas for improvement. Continuous Improvement isn’t about making huge changes all at once but making small, incremental improvements consistently. This approach reduces the chances of resistance to change and increases the likelihood of successful implementation of improvements.

The Feedback Loop is another central concept related to Retrospectives. It involves gathering and utilizing feedback from all team members, stakeholders, project outputs, and project processes to assess performance. In Retrospectives, the team discusses any feedback received from the completed sprint or project, typically focusing on three areas: what went well, what didn't go well, and what can be improved. The Feedback Loop then involves implementing changes based on this feedback in the next project or sprint, whereby creating a cycle of continuous improvement.

Team Alignment reflects the shared understanding and common goals among team members. In Retrospectives, this involves revisiting the team’s goals and outcomes for the project or sprint and discussing how the team's actions aligned (or didn’t align) with these objectives. Open and honest discussion helps to address any misalignment among the team. The outcomes of these meetings should result in a shared understanding of the team's performance and improvements to be made, leading to better team alignment for future projects or sprints.

Root Cause Analysis refers to the method of identifying the key reasons why an issue occurred. This method is often used in Retrospectives to understand the underlying causes of project or sprint weaknesses. This goes beyond identifying what didn't go well – it’s about understanding why it didn't go well. Once the root causes are identified, preventive measures can be put in place to mitigate such issues in the future. This deepens the team's understanding of the project and encourages proactive problem-solving.

Action Planning is the stage in Retrospectives in which the team determines what specific actionable steps they will take to implement the improvements identified. This includes who will do what, by when and how progress will be measured. With action planning, the team moves from reflection to action, making the Retrospective productive and goal-oriented. This focus on practical, feasible actions increases the likelihood that improvements will be effectively implemented in the future.

Retrospective Facilitation involves managing the retrospective meeting effectively to ensure a productive discussion and derive meaningful and actionable takeaways. The facilitator, usually the Scrum Master, needs to create a safe environment where team members feel comfortable sharing their thoughts and feelings. Different techniques, such as the '4Ls - Liked, Learned, Lacked, Longed For', Plus/Delta, and 'Stop, Start, Continue' can be used to facilitate the discussion. He or she also manages time effectively, makes sure everyone has equal space for expressing their thoughts and ensures the conversation remains constructive.

Inspection is a fundamental concept in Agile retrospectives. It refers to the process of reviewing and assessing the team's performance during the sprint. This includes evaluating the effectiveness of processes, tools, and methodologies; measuring the quality and timeliness of deliverables; inspecting team dynamics and collaboration; and analyzing any obstacles the team encountered. The goal is to identify areas for improvement and create an actionable plan to address them. The focus on empirical process control necessitates frequent inspection of the work and the workflow.

Adaptation is one of the fundamental pillars of Agile development and an important aspect of the retrospective. It is the act of making changes based on the findings from the inspection. Adaptation can mean modifying processes, altering team dynamics, or even changing the product goals, based on the findings from the retrospective. The goal is to improve productivity and enhance the quality of the product incrementally and iteratively. This constant cycle of inspection and adaptation drives continuous improvement, a fundamental principle of Agile development.

Transparency is crucial to effective Agile retrospectives. This means that all team members should have a clear understanding of what is being done, why, and what the expected outcomes are. Transparency allows for clear communication and understanding among all team members, which enables effective collaboration. It also supports mutual trust and openness, which are necessary for a productive performing team. During retrospectives, it encourages team members to share their views openly and without fear, which helps in revealing hidden issues and generating a healthier discussion.

Collaborative problem-solving, another important concept in retrospectives, emphasizes the importance of the team working together to identify issues and find solutions. It is aimed at harnessing the collective intelligence of the team to gain more insights and develop more effective solutions, as opposed to individuals working in silos. It helps in developing a shared understanding of the challenges and ensures buy-in from all team members for the proposed solutions, thereby increasing the chances of successful implementation. This concept also promotes team learning and helps in building a more cohesive team.