Manufacturing Strategy
 - Part 8: Quality management techniques & tools

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Introduction

Last month I described how quality management was fundamental to a successful company and how financially important it was to manage quality. No doubt all the readers nodded at the right places and then went off to do a bit of fire-fighting and alligator wrestling, when really they should have been draining the swamp.

We have all heard the words and have agreed, but so few in our industry have taken really significant action. It is important to note that I do not class achieving ISO 9002 as significant action for quality improvement despite all the good things I can say about it. A quality management system is only one of the building blocks for quality and although it provides a framework for improvement it does little to actually improve quality. In many cases ISO 9002 is used to reinforce the 'status quo'. Most companies achieve ISO 9002 but do little towards improving quality, instead they have a big manual that formalizes their existing procedures and serves to make change and improvement difficult.

One of the reasons for this is that there are many perceived barriers to actual quality improvement. The real problem often breaks down to a lack of knowledge of the tools or management methods to use to improve quality. This article deals with some of the quality management tools.

  The quality action cycle

One of the first things to be done is to set the scene for using quality tools by instituting a formal quality action cycle as shown in Figure 1.

Figure 1: The quality action cycle

The cycle can be used via the following statements:

  1. We will take no measurements without recording the results.
  2. We will not record results without analysing them.
  3. We will not analyse results without acting on them.
  4. We will not act without measuring the results of our actions.

This cycle provides the formal method for improving every aspect of our business based on evidence and analysis. It can be used in all areas of the company.

The 7 quality tools

These are the tools that are used to identify concerns, record results and analyse results to define the actions. Only you can decide how you will act and in many cases the problem is not that we do nothing but that we do something that makes the problem worse. In quality management, as in personnel management, the only important things are motivation and direction, but if your people are facing in the wrong direction then for goodness sake don't motivate them! The 7 Quality Tools allow us to provide this essential direction and they are shown in Figure 2.

Figure 2: The quality tools

It is not possible to give a full description in this page but further descriptions are given in The Managers Toolkit Series. The descriptions here are brief to put the topic into the manufacturing Strategy framework.

Identification

The first set of tools is used to identify areas for improvement.

1) Flow Charts

It is possible to create a flow chart of any process or operation to show how work happens. This is particularly useful for quality improvement because when you can see what happens in a process you can begin to improve the process.

Flow charts are widely used in computer programming to lay out how the programme operates and to provide an overview of the program. This makes them very useful in industrial process improvement. Generally when we decide on how to do jobs in our factories we just let them evolve and hope that they will turn out to be efficient. Flow charts force us to think in a very orderly manner and structure the thinking process. If you construct a flow chart based on 'yes' and 'no' answers then you must really think about the process. As a general rule the areas that cause difficulty when making the flow chart are also the areas that give quality concerns. If you, as a manager, have difficulty in drawing a flow chart then how can you give clear and unambiguous instructions to your workers?

2) Check Sheets

One of the problems of identification is that we rarely know where to begin, we all tend to have ideas but there is little hard evidence and we act on hunches rather than on evidence. The action cycle says that we shall not measure without recording and check sheets provide an easy way to record and analyse your results. A check sheet is basically a form that you fill in with the results of your observations. It must include who collected the data as well as the time it was collected. Cheek sheets also act as the start to the analysis process and can help to structure your data prior to the analysis process.

Identification and analysis

The second set of tools is used for both identification and analysis.

3) Pareto Principle

This is the classic 80:20 rule that many of you will be familiar with i.e. in broad terms: 80% of your installation problems concerns will come from 20% of the jobs, 80% of your concerns will come from 20% of your operators (or operations or products), 80% of your profits will come from 20% of your customers. Identification and analysis via Pareto enables us to separate the 'the vital few' from the 'trivial many' and to take action for the best returns. Pareto is probably the most powerful tool you can find for making a hero of yourself in quality improvement.

4) Cause and Effect Charts

These are also known as Fishbone Diagrams or Ishikawa Diagrams and are used to list possible causes and to rate their importance. The basic idea is to take a range of broad headings (such as Men, Materials, Methods, Machines and Measures) and to use these to group possible influences on the end result. The method is a very specific development of 'brainstorming' that is targeted on improving an effect by listing all the possible causes. Cause and effect charts are best used by actual operators who have real knowledge of the process. The method can be used as a sophisticated way of 'picking the brains' of the best operators to give real process improvements.

Analysis

The third set of tools is used for analysis of results and decision making.

5) Statistical Process Control (SPC)

Statistical process control recognizes that any manufacturing process is naturally variable and that it is impossible to predict the value of any one characteristic at any one time. Statistical methods take simple process data and use it to describe the process itself rather than describing each individual article. Control the process quality and the product quality automatically follows.

During the Vietnam War the USA introduced a 'hearts and minds approach' to convince the people that democracy was the way forward. Gen. Westmoreland (the US commander in Vietnam) was not in favour of this and adopted a more direct approach. He said that if you 'grabbed them by the balls then the hearts and minds automatically followed'. SPC grabs the process by the balls and the product quality automatically follows.

SPC is a unique tool to give confidence that parts are being produced within tolerance, without having to measure every part. SPC hands control back to the operator and acts as a 'feed forward' control.

6) Scatter Plots

Scatter plots are a quick and dirty way of seeing if two variables are related. The idea is not to plot a graph and establish a direct relationship but simply to get some points on a piece of paper and see if the cause and effect are related.

7) Histograms

Histograms are a form of graph that can communicate a lot of information at a glance. They are basically a form of bar chart based on the recorded values of a variable and are probably the easiest graph type to under-stand. The value of histograms lies in the ease of understanding for all levels of the workforce.
There are other quality tools that you can use, such as Poka Yoke (Mistake Proofing) which is great for assembly operations, but the important thing is to start on quality improvement as soon as you have a quality system in place.

Quantified total quality (qtq)

The QTQ concept broadens the traditional thinking to include the service levels offered in the customer/supplier relationship. QTQ is said to provide rapid improvements to justify the investment in the programme and hence provide the incentive to attain the long-term benefits.

QTQ requires ownership by the managers who will be responsible for implementing the changes and provides the framework within which management provides the example, leads the process and makes things happen.

QTQ goes back to the Key Factors for Success and business goals and seeks to apply a targeted approach i.e. don't get great if the rewards are not worth it. In QTQ the goals are then translated into a series of external and internal customer needs with an evaluation of the service provided (by the customer). This then allows a very customer orientated focus on the concept of total quality.

Data on the activities undertaken is gathered and activities are divided into core, support and discretionary activities. By using the customer assessment more activity can be channeled into the core activities to give improved effectiveness and an improved perception of quality. In most cases this involves examining the service levels provided to the customer to achieve the right level. A key objective is to realign management away from supervising the quality of their group's output towards a role of continually working with their staff to improve the focus and direction of the process.

Summary

As people we all react in the same way, if my boss tells me that quality is all-important and then measures me according to my production output then what do you think I will concentrate on improving? The truth is that people react in the way you inspect and not in the way you expect or people react in the way you audit and not in the way you plaudit. If we really want to improve quality as opposed to simply talking about it then we have got to measure our quality and display the results. Put in another way 'what gets measured and displayed, gets done'.

Real quality management and improvement involves a culture change as broad as that involved with JIT or other production management processes. We need to realize that our services and products will only be required as long as they meet the customer's demands. The only other sure thing is that tomorrow's demands will be higher than those of yesterday and that, rather than being a 'winner', excellence will only be a ticket to the game.

"The Manufacturing Strategy" Series

"The Manufacturing Strategy" series is designed to give production managers and their staff some insights into new manufacturing methods and to prompt the industry into considering the benefits of alternative approaches to manufacturing. The series is:

Part 1: Setting the strategy

Part 2: The systems and MRP II

Part 3: Just in time (1) 

Part 4: Just in time (2) 

Part 5: Just in time (3) 

Part 6: Optimised Production Technology (OPT)

Part 7: A fundamental quality

Part 8: Quality management techniques & tools (This section)

Part 9: ‘There's no accounting for manufacturing strategy’

Part 10: Performance measurement

Part 11: Changing roles and things to do NOW!

 

Last edited: 11/03/10

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