What are the best tools to identify process bottlenecks?

Process maps can be as detailed as you need them to be. If you're looking for bottlenecks, I recommend you include timelines and dependencies on your maps. You'll be able to see where time can be saved and which issue should be tackled first.

The 5 Whys is one of the simple techniques that anyone can employ to get to the surface of process bottlenecks. In a 5 Why approach, the goal is to get as deep as possible to the potential causes of bottlenecks by repeatedly asking why. The 5 in this problem solving process is just a rule of thumb. Sometimes even 6, 7 or more whys can give you greater chances of coming as close as possible to the best solution options. In a problem diagnosis exercise it is important to catch surface and deep layered problems, perceived and the real problems. Those that are articulated and those that are not.

Process Bottlenecks could be related to economic impact, risk management issues, HSE management issues, waste materials handling issues (such as NORM handling in the Petroleum Industry), ground water management related issues, apart from quality and performance of the end product.

Process simulation is, by far, my favorite tool to identify bottlenecks in a process. It is based on Monte Carlo simulation techniques, therefore, it considers the different variability that the different factors (demand, capacity, lead time, etc.) can have. When identifying the bottleneck in the process (the step that has the less throughput or the highest time), try using different techniques (such as design of experiments or TOC) to reduce the bottleneck and increase the process capability efficiently.

The Kepner-Tregoe method is a valuable process improvement approach that consists of four fundamental steps: 1.Situation Appraisal: the problem and the objective are clearly defined to provide a clear focus. 2.Problem Analysis to identify its root causes. By understanding the causes, effective solutions can be developed. 3.Decision Analysis: different alternatives are evaluated, considering their potential consequences. Pros and cons are weighed, risks are assessed, to choose the best action based on objective criteria. 4.Potential Problem Analysis: potential risks associated with the chosen solution are identified. Contingency plans and preventive measures are developed to mitigate these risks and ensure smooth implementation.

First to identify process outcome. Then to identify the value proposition as per customer expectations. Preparing value stream map and breaking down the process in smaller steps basis milestones which are clearly distinguished. Further, value stream mapping can be deployed to analyse and to identify improvement opportunities.