''I believe that all stages of the project lifecycle are essential and the project's success depends on the completion of every phase from initiation to closing. Failure in any phase will cause the failure of the project. Because, the outcome of the previous stage is the input for the next stage (PMI, 2017).

Nevertheless, I believe that the initiation phase is the most impactful for the project's success because during this phase the foundation for planning and execution is prepared. If the feasibility study or project charter is poorly developed, it will with high probability cause issues during future stages. Islam et al. (2011) in their article analyzed dependencies between initiation phase processes and the success of the project and came to the conclusion that if the feasibility study is done by the specialized organization it positively affects the success of the project. Sometimes it is wiser to stop the project at the very start and not spend valuable resources on a project that had no chance of success from the very beginning. Referencing my experience in the construction area in Russia, the importance of the initiation phase is often undervalued. The most common mistakes in my career were not a specific estimation of scope and not having predefined approval procedures for scope change (who and by what procedure can change the scope). This always transformed into scope creep and affected the project's time and budget. That is why I believe methodology is most impactful at the initiation phase. If the project manager passes the initiation phase according to methodology and mindfully creates the project charter and feasibility study this will not guarantee but will increase the chances for the success of the project (Islam et al., 2011).

Coming to the second part of the question, as we are discussing in the PMBoK context, I would like to emphasise that the PMBoK is not the methodology itself. PMBoK is a knowledge base, the standard describing essential processes, "good practices" and the project management approach. According to the project type, the project manager must define and apply the correct methodology (Wysocki, 2019). The project life cycle is an essential component of the project management methodology. It can be described as a series of stages or phases every project sequentially goes through from initiation to closing. Depending on a project and the methodology life cycle can be predictive, iterative, incremental, adaptive or hybrid. Every project is unique therefore methodology should be tailored to suit this exact project. (PMI, 2017).

To select and tailor the methodology to the exact project a lot of facts should be taken into consideration, such as the goal and planning outcomes of the project, the solution for attending the goal, the type of the project, the industry, the environment, the length of the project, the scope, involved resources, stakeholders, budget, etc. (Wysocki, 2019).

Traditional predictive or plan-based methodologies with the waterfall concept suit projects where goals can be clearly defined in the initial stage of the project lifecycle. A simple example of such a project is the construction of a building. Thus if the goal is evident from the kick-off and the work can be clearly planned and specified traditional approach is preferable. But if the result of the project can not be clearly defined at the beginning, an iterative Agile approach fits better (Thesing et al., 2021). This approach will suit software development or R&D projects where the project's end result is not evident at the initial stage. In such a project team will repeat the development looped process step by step. At the start of every loop goals and deliverables can modify according to the achieved results of the development process. And at the end of every loop team will wait for feedback for approval or correction if our development is moved in the wrong direction. Nowadays hybrid methods (a mixture of traditional and Agile) are becoming more popular as they can add more flexibility to predictive methodologies (Wysocki, 2019).

To conclude, I believe that to execute the project successfully project managers should use PMBoK best practices and processes with alignment to the exact unique project. They should tailor and adopt PMBoK to the needs of the project and use only techniques and methods that are really needed. It is not necessary to use everything. Depending on the project they should choose traditional, Agile or hybrid methodology (Islam et al., 2011)''

Give an opinions with references to either criticise or justifies the case study