### 5.5.1 Frequency and Duration The frequency of an Iteration Retrospective is aligned with the other ceremonies that aim to prepare and evaluate an iteration. Just like the Iteration Planning and the Iteration Review, the Iteration Retrospective happens once every iteration. Since the goal is to inspect what happened during the iteration and find opportunities for improvement, it’s not a surprise that this ceremony takes place at the end of the iteration. This will allow the Agile Project Core Team (A-PCT) to collect as much data as possible and analyse it during the meeting to help generating important insights. The duration of the Iteration Retrospective depends on several different factors. - **Size of the team** – It seems natural that the more Agile Team Members (ATeM) participate in the Iteration Review, the more inputs will be collected, which means more time needed to analyse and process them. - **Size of the Iteration** – With longer iterations, it’s more likely to have a higher number of events or other topics the team wants do discuss, which means, in theory, more time is required. - **Level of stress/friction** – Depending on the level of stress, controversy and other distressing aspects, more time must be put aside for the Agile Team Members (AteM) to vent. While other factors may also impact the duration of the Iteration Retrospective, it’s very important to ensure that the time allotted to each of the sections of the meeting is observed, otherwise the Retrospective may not generate the desired outputs. Still, PM2-Agile suggests a duration between 60 and 120 minutes depending on the factors described. The next section provides detailed information about the structure of the Iteration Retrospective.