Benchmark Six Sigma Expert View by Venugopal R
FMEA is a very popular tool used for Risk Analysis, whereas PDPC (Process Decision Program Chart) has been released by JUSE (Union of Japanese Scientists and Engineers) as early as 1976. While the Process FMEA is useful to analyze the potential risks (failure modes) associated with a process, the PDPC is a tool that helps to assess the risks associated with a Project.
The Process FMEA begins by listing the process steps and identifying the potential failure modes during each process step. Process FMEA has its inbuilt quantification methods by considering the ratings for Severity, Occurrence and Detection associated with each failure mode and gives a composite Risk Priority Rating (RPN).
PDPC is much simpler tool than Process FMEA, and it not only identifies the potential failures, but also the possible counter measures and ends with selection of the feasible counter measures.
While we manage complex projects in which the impact of even small failures could be very high, it is very important to foresee potential risks and do an advance mitigation planning.
The first step to prepare a PDPC is to develop a tree diagram of the project. The tree diagram begins with the overall objective on the top box. This is the first horizontal level of the PDPC. In the second level, we need to branch out from the overall objective, the major activities that are necessary to accomplish the objective. The third horizontal layer will be the tasks that branch out from each of the activities represented in the second layer.
Having created the above 3-layered tree diagram up to ‘task level’, we need to do a ‘what-if’ analysis and identify what could potentially go wrong with each of the tasks. This has to be done by brain-storming using the experience and knowledge of the people and other experts connected to the project. Some of the questions that may be asked to identify the potential failures are:
If this task were to fail, how could it go wrong?
What is the primary intent of this task? Can it result in doing something else, instead or in addition to its primary intent?
Have we allowed for any margin for error?
Are there any assumptions made?
Do we have experience from similar situations?
The identified risks are included in the tree diagram at the fourth level. The team may review these risks and remove the ones that may be very improbable. The counter measure for each risk is identified as the fifth level in the tree diagram.
The figure shows the structure of the PDPC tree diagram with the five levels.
For each counter measure weight the feasibility considering, cost, time, effectiveness and ease of implementation. Mark the countermeasures that are finally selected as ‘O’ and the ones eliminated as ‘X’