Control and Dominance

3985 reads

 Process control is very important to ensure quality of products, but to ensure better process control it is vital to understand the dominating variables in the process and plan control mechanism based on the same.

When we talk of Process Control and plan to initiate it in our operational processes, it is important to understand the variables that most affect our processes. The process designers must identify the vital few controls that will receive priority, and for this designers and operational personnel must understand the concept of dominance.

 

Processes are influenced by various input variables like environment, skill, setup and many more; and often one variable is more important than all combined and such a variable is called dominant variable. In the book "Juran on Quality by Design", Juran classifies these dominant variables into five types, which we are listed below:

 

* Setup-dominant: Processes which once set-up will exhibit stability and reproducibility over repeated cycles of operations are know to be setup-dominant processes. These processes must be so designed that importance is given for precise setup and validation before operations proceed, because there is no real control during the repeated cycle of operation that will impact the quality of the output. For example in the printing process, once the setup is made and approved the operator has no influence on the spellings, font size or other parameters on the printed matter. Similarly in the manufacture of plastic molded parts, wherein the manufacture of the mould ( tool ) plays a vital role and is also called tool dominant process.

 

* Time-dominant: In this case the process is known to change progressively with time, this is typical of machining processes wherein there is wear out of tools over a period of time, similarly consumption of consumables, heating up. The process design must take into consideration the periodic evaluation and adjustment of the process. Process Control charts are most commonly used for time dominant processes.

 

* Component Dominant: The main variable in this case is the quality of the input materials and components. This is typical in assembly processes like assembly of mechanical and electronic equipments; like assembly of a television. Many organizations resort to incoming inspection to bring control, though this is probably required for a short time, in the long run it is important to develop suppliers to provide quality parts. Joint planning with suppliers to improve supplier's process will also be required.

 

* Worker Dominant: When the quality of the output depends mainly on the skill and knack possessed by the workers, it is called a worker dominant process. For these processes the candidates employed are almost always form qualified with the basic skill sets. The design for control of these processes must emphasize aptitude testing, training, certification and quality rating of workers. Well, training and certification is indeed important for all types of process, but in this case it is even more important.

 

* Information Dominant: In this case the processes are of "job shop" nature, wherein there is frequent changes in the products that need to be produced. Since the job information changes frequently, the design for process control should concentrate on providing an information system that can deliver accurate, up-to date information on just how each job differs from the others.

 

A common mistake I see people make while solving process problems and customer complaints is to attribute the problem to "operator error", no matter on what type of dominance the process is. Even in worker dominant process it is important for us to see how much of control we can bring by error proofing the processes, so that there is less and less of operator influence. Process control is very important to ensure quality of products, but to ensure better process control it is vital to understand the dominating variables in the process and plan control mechanism based on the same. 

 

pradeep-kumar-e.tPradeep Kumar E.T. A Master Black Belt in Six Sigma , is the Country Manager- Operational Excellence with Tyco Electronics Corporation India Pvt Ltd. Feedback can be e- mailed to pradeep@ businessgyan.com

Issue BG89 Aug 08

Trending

194
adamgrant's picture

Most Personality Quizzes Are Junk Science. I Found One That Isn’t.

Most Personality Quizzes Are Junk Science. I Found One That Isn't."The MBTI is astrology for nerds." Say it with me again: personality types are a myth, traits are on a continuum, and the major dimensions include extravert-introvert, agreeable-
205
changethis's picture

What If Sellers Behaved as Leaders?

“It is time we start making a shift. Research shows you can make more sales by abandoning sales-y behaviors buyers resist and replacing them with leadership behaviors buyers desire. Sellers do extraordinary things when they stop pushing people to
264
adamgrant's picture

Is Curiosity As Good at Predicting Children’s Reading, Math Success as Self-Control? Study Says Yes

The joy of discovery matters as much as self-control, and matters even more for low-income children. We need to encourage kids to ask novel questions, not just give familiar answers.Ever since the landmark "marshmallow test" highlighted the
212
danielhpink's picture

PINKCAST: This is when to quit your job

Should you stay or should you go? After a few years at the same job, many of us begin asking that question.In the latest Pinkcast, former Wall Street analyst and venture capitalist Whitney Johnson offers the answer. You can watch the 136-second
213
changethis's picture

The Speed Trap: When Taking Your Time (Really) Matters

“Speed-for-speed’s-sake is about the most counterproductive* approach imaginable. (*I use counterproductive because it’s impolite to use “stupid”—which is what I really believe.)While we must indeed evolve and experiment rapidly, the process of
318
adamgrant's picture

How to Pick a Career (That Actually Fits You)

This is a post about something I’ve been wanting to write about forever: careers. Society tells us a lot of things about what we should want in a career and what the possibilities are—which is weird because I’m pretty sure society knows very little
252
danielhpink's picture

WHAT TO LISTEN TO: Some audiobooks are more equal than others

“Mr. Jones, of the Manor Farm, had locked the hen-houses for the night, but was too drunk to remember to shut the popholes.”So begins Animal Farm, George Orwell’s classic novella. I’ve read Animal Farm many times. But now, for the first time, I’m
245
changethis's picture

Beyond Business Results: Achieving Sustainable Success

“For most of my career, I focused on my next professional opportunity rather than on my present situation. I was committed to serving patients and to helping my company meet its goals; I was always looking down the line to what was coming next. What
262
danielhpink's picture

WHAT TO WATCH: The Happiest Guy in the World

Two decades ago, Mario Salcedo retired from his job and went on a cruise. He never came back. Mario wasn’t lost at sea. For more than 20 years, he's been a permanent resident on Royal Caribbean Cruises. You read that right. “Super Mario” has