Q. 126  While implementing Lean, abnormalities need to be highlighted. If "Nominal conditions" are not finalized for a process, it is virtually impossible to highlight what should be considered abnormal. Explain what goes into defining "Nominal conditions" and what are common challenges in finalizing them.  

 

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For any process or department we must know and highlight abnormal conditions which needs to to eliminated. And to recognize abnormal, it is must to understand what normal is. Nominal condition defines standard of process on which it s operating within acceptable limits. It is a very important concept and we have to understand better what nominal condition is.

 

The first thing to define Nominal condition is to establish acceptance limits. For example, we know that parts are producing from different tools which have different rate of production or has different SPM(Strokes per minute), A part of high SPM of 12 will be produced 720 units in one hour on the other hand a part of low SPM of 8 will be produced 480 units only in one hour. SO we should define limit because at the end of that day we are knowing that we will achieve our target .

 

other example for the same is rules change by government in Engines from BS4 to BS 6 before it was BS 3, every time they are giving some acceptable limits for emission control so that companies do modification accordingly and set their target and range accordingly during production. 

 

The second important key to define nominal condition is to be able to measure it in process metric. For example machine has a capacity to produce 4000 parts in eight hour and so every hour it should finish 500 parts, so if you are knowing that at particular time you are supposed to finish 2000 parts but you are behind that target it means you are out of your Nominal condition. One should be able ot measure the condition real time e.g. at the mid hour mark - what is the count which gives you the opportunity for correction. It is hard to correct when the measurement cannot be real time (or with lagging measurement)

 

The most common challenge is to maintain it for a long time. Mostly people think that it is one time activity and left after achieving it, but actually it is day to day activity and there are chances of continuous improvement. Like Toyota has implemented it long time back but still they are continuously working on it to improve it further and to maintain it further.

 

Mostly people think that this can be used in manufacturing facility only but it can be used in any department of the company. There may, however be a lot of resistance to such a change.

As we understand, the key objective of LEAN process is to eliminate "waste" or "non-value added" activities within a process. 

In order to achieve this, we need to clearly differentiate between what is value add vs. non-value add OR required vs. not required OR normal vs. abnormal. 

The process of defining what is normal or in other words defining standards or specification limits for the process is called as Nominal conditions.

In order to define nominal conditions we basically need two things
1. Set the acceptance limits and 
2. Able to measure these acceptance limits.

As we are referring to a LEAN process, it is quite possible that we have to set these conditions across all drivers for the process i.e Material, Method, Machine, Man and Measure. 

 

The possible challenges of a Nominal condition is that it has to be frequently evaluated at every stage across drivers to ensure nominal conditions are met. 

 

While it is fair to assume that, such a condition could possibly be tried in a manufacturing set-up, for other industries and administrative processes it is difficult to implement. An example I can think through is, for a Judiciary system, it is difficult to set target for the number of trials before you acquit or convict a suspected trial. 

While this is an important concept, it's something not used more frequently or directly.

Vastupal Vashisth has mentioned the two requirements for setting up nominal conditions and provided a clear example, and hence is the chosen best answer.