Control Plan

[Vishwadeep Khatri 265]

Q. 136  What is the best way to create a Control Plan for a process? 

 

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[Vastupal Vashisth 34]

Control plan is a quality document which is part of PPAP and its a method for documenting all the functional elements  in the process to assure quality standards are met for the desired product or output of that process. 

 

The best way to create a control plan is its development by the cross functional team, that has the understanding of the process which we are going to execute or controll. With the help of CFT, we can identify opportunities for improvement. Control plan is more than just a document, it is that plan which is created by or developed by the CFT team to control the process form input to output and ensure that the process produces quality output/products that meet the customer requirement. 

 

CFT team should consider observation/output/know-how from following to create a good control plan.

 

• We should consider process flow diagram to consider each step involved in the process to control it 
• Consider the output and previous know -how from DFMEA
• Consider the output and previous know how-how from PFMEA
• Consider quick learning form previous similar parts, processes
• Do design review
• Knowledge of the team about the process and part or output
• Consider special characteristics

Control plan must be living document because all the information and problem history changes throughout the life cycle of the process. We should continuously update control plan as per input form any process step or something new happened which was not there earlier.

[Venugopal R 67]

                    Benchmark Six Sigma Expert View by Venugopal R

 

Let me attempt to narrate the unfolding of my understanding of control plan over past 3 decades….

 

Maybe, my first introduction to the term “control plan” was through ISO 9000 standards released during the late eighties.

 

However, I had worked with an auto ancillary prior to that, where we had a collaboration with a Japanese organization for setting up manufacturing of an auto component, that I believe was for the first time in India. As part of the technology transfer, one of the key documents that we received was a lengthy, multiple folded, handwritten, tabulated document with all the process steps outlined, the quality characteristic for each stage of the process, the specifications, the method for evaluating compliance to the characteristic, and the sampling recommendations. I am not sure whether this document was named as “control plan” at that time, but I always remember this document, during subsequent stages of my career when I formally got introduced to control plan and whenever I associate with control plan.

 

This only proves that this tool, whatever it might have been named in those days, was part of the good Japanese production practices, from very early times. And, more importantly, it found its place among ‘most important’ documents required for a technology transfer.

 

Subsequently, the automotive industry came up with a set of QS9000 standards, along with which emerged the APQP (Advanced Product Quality Planning) standard. The APQP provides a good framework that gives clarity about the creation of Control plan and its linkages and sequence with respect to other methodologies.

 

The APQP goes through five phases after a pre-planning phase

1.     Plan & Define

2.     Product Design & Development

3.     Process Design & Development

4.     Product & Process Validation

5.     Feedback assessment & corrective action

 

The Product Design & Development section includes DFMEA and Design verification plans. The Process Design & Development phase includes PFMEA and the proto control plan formation begins here. The Process and Product validation phase includes the Evaluation Methods, MSA, setting up Statistical Process Controls, all of which are inputs into the control plan. The Production Control Plan is an output of the APQP at Phase 4.

 

It is evident from this approach that 'control plan' needs to have plan for:

1. Systemic controls (for instance effectiveness of mistake proofing systems needs to be validated from time to time)
2. Process controls (for example, a thermostat-based temperature control needs to be validated periodically)
3. Human based controls
4. Reliability of measurement systems
5. Reaction plans for any non-conformances

 

If we need to have dependable control plans for all the above, the inputs for the control plan has to evolve from the above-mentioned phases of APQP.

 

Some of you may wonder why control plan should be seen only from the context of a Quality System associated with auto industry. It is for the conceptual clarity that may be obtained from the framework of APQP and how the control plan gets derived. The same concept can be adopted for any industry, including Information Technology services.

 

The control plan will remain as a live document that will keep getting updated in line with the levels of knowledge maturity.

 

I conclude by saying that although the concept of control plan has existed even several decades ago, we have many avenues that have brought very refined clarity on the pre-requisites, building and executing a control plan effectively.

[Hari Shyam Gupta 0]

Control plan is a document that provides the list of measurements, inspection and quality checks to be done through the process at different phases so that it conforms to the required specifications and reduces the possibility of non conforming output. It saves cost of processing and time and cost of rework.

 

Control plan can be developed be following procedure.

 

1. Review the PFD (Process Flow Diagram).

2. Review DFMEA

3. Review PFMEA

4. Review special characteristics matrix.

5. Review lessons learnt documents.

6. Brain storm within the team.

[Rupinder N 31]

The chosen best answer is that of Vastupal. Read Hari Shyam's answer for a very succinct overview of how a control plan can be developed.