The FAQ on Engineers and Quality
- What is Quality?
- How does one achieve Continuous Improvement?
- What is Design of Experiments?
- What is Statistical Process Control?
- What is Just-in-Time?
- What do I really need to know about Total Quality Management?
- What is Quality Assurance?
- What is ISO 9000?
What is Quality?
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Nobody knows. :-)
Quality is that aspect of your product or service which the
customer most wants. For this reason, your customers know more
about quality than you do. You cannot define it apart from your
customers. Guaspari puts it this way:
They're not buying a product. They're buying your assurances
that their expectations for that product will be met. And you
haven't really got anything else to sell them but those
assurances. You haven't really got anything else to sell
but quality.
While many authors have contributed to the field of quality in
this era, the one perhaps most often pointed to as being
responsible for the mania we know today as Total Quality
Management (even though he swore while he was alive that he had
nothing to do with it) is W. Edwards Deming. Deming, who built
his business and reputation helping Japanese industry recover
from World War II, developed what he referred to as a "system of
profound knowledge" that would enable managers to lead their
organizations to quality. The system of profound knowledge
consists largely of
- Some grounding in statistics fundamentals, resulting in an understanding of the nature and sources of variation.
- Some knowledge of systems engineering, resulting in an appreciation for interactions between subsystems.
- Some idea where knowledge comes from and how it is passed on, resulting in an ability to teach and lead by example.
- Some knowledge of psychology, resulting in the ability and desire to help people change current practices and move into a new way of thinking.
Deming's 14 Points for Management (per Out of the Crisis) are as follows:
- Create constancy of purpose toward improvement of product and service, with the aim to become competitive, to stay in business, and to provide jobs.
- Adopt the new philosophy. Western management must... take on leadership for change.
- Cease dependence on inspection to achieve quality. Eliminate the need...by building quality into the product in the first place.
- End the practice of awarding business on the basis of a price tag. Instead, minimize total cost. Move toward a single supplier for any one item, on a long-term relationship of loyalty and trust.
- Improve constantly and forever the system of production and service, to improve quality and productivity, and thus constantly decrease costs.
- Institute training on the job.
- Institute leadership -- the aim of supervision should be to help people and machines, and gadgets) to do a better job.
- Drive out fear.
- Break down barriers between departments. People in research, design, sales and production must work as a team to foresee problems in production and use.
- Eliminate slogans, exhortations, and targets for the work force asking for zero defects and new levels of productivity.
- Eliminate quotas, management by objective, and numerical goals.
- Remove barriers that rob workers of their right to pride of workmanship. Abolish merit ratings (and performance appraisals).
- Institute a vigorous program of education and self-improvement.
- Put everyone in the company to work to accomplish the transformation.
Adams (in The Dilbert Principle) adds that individuals
within the company should avoid as much as possible involvement
in anything not directly related
to (a) employee effectiveness or (b) product quality. This often
includes serving on quality teams. :-)
What should we all know about quality?
There are three scientific aspects of quality which I recommend
we learn -- not in detail, but conceptually only will do fine.
They go to what data gets collected, what analysis gets done, what
conclusions can be drawn from the analysis, and to what degree of
certainty. I have them listed in order of what I see as their
importance to the company, and coincidentally that's also the
order of how well I know them myself.
- Statistical Process Control
- Design of Experiments
- Theory of Constraints
How does one achieve Continuous
Improvement?
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Deming says "improve constantly and forever your product and
system of service." This is most effectively done by
concentrating on "bottlenecks" in the process you are trying to
improve. Bottlenecks in a process are analogous to overloaded
members in a structure, or overloaded circuits in an electrical
system: the process is only as effective as its slowest
bottleneck -- as a chain is only as strong as its weakest link.
How do you know whether you have a bottleneck? Measurements
(known in the literature as metrics) are necessary -- and not
simply cost. There is no organization that has the goal of
minimizing its costs. If this were the goal of any organization,
then that organization could achieve maximum performance
immediately, by going out of business. The use of cost as a
metric focuses management attention, and bases local decisions,
on something that is not the goal of the organization.
One right set of measurements is defined by E. M. Goldratt, the
originator of the Theory of Constraints:
| Goldratt's Measurements | |
| TERM | DEFINITION |
| THROUGHPUT | sale price minus raw material cost |
| INVESTMENT | all money trapped in the organization |
| OPERATING EXPENSE | money spent to generate throughput |
Throughput is (again) not necessarily money. It could be "health
units" (for a hospital) or "education units" (for a school) or
"satisfied customer units" (for a business). But this is the
metric that you base continuous improvement on, while trying to
hold investment and operating expense nominally constant (though
there may be capital expenditures necessary for "optimal"
process improvement).
The Theory of Constraints (TOC) suggests that for any process,
the bottleneck can be modeled as a constraint on throughput.
Relaxing the constraint is not
the same thing as firing inputs at the bottleneck at
the fastest rate -- it is rather to maximize the throughput
per unit time at the bottleneck. The following process from
the TOC summarizes the necessary steps toward continuous
improvement:
- Identify the constraint. This can be a policy as well as a physical bottleneck.
- If the constraint is a physical bottleneck, then exploit it fully -- maximize its throughput. This may involve determining an "optimum" mix of products or scheduling of the production line. If the constraint is a policy, find a way around the policy.
- If the constraint is a physical bottleneck, then subordinate all operations to your decision to exploit the constraint. Get everyone involved in the process to cooperate with the effort.
- If the constraint is a physical bottleneck, and if you've already performed the first three steps, then increase the capacity of the constraint.
- If during step 4 you've increased the constraint's capacity to the point that it is no longer the constraint, then go back to step 1 and begin the process all over again.
In fixing bottlenecks, it's important to remember that overdesign
of the fix may waste time and money. You want to correct the
bottleneck enough that it doesn't have to be corrected again in
the near future. Having done so, you find the next bottleneck
reveals itself -- if it hasn't already. (There is no need to
identify them all at once, since you will be correcting only
one.) But the tendency toward optimizing every decision is
itself a bottleneck, and is a chief cause of "TQM burnout" in
organizations.
To look at the whole system as indicated above assumes you're
the "puppet master" -- that you know all the steps in the
process and have authority to change them. This may not
actually be the case. Which is why Deming says "adopt the
new philosophy." Leadership must come from the top -- from the
one who IS the puppet master. Continuous improvement can thus
be implemented by individuals who are puppet masters; or by
small teams when they are empowered to do so and are effective;
or by large teams when those teams have systems engineering
capability, and are monitoring the overall process. Small and
large teams can act as puppet masters over certain processes.
The implementation of that complete solution will require the
cooperation of many who are not on the team, and of many higher
level managers who aren't even in the team's organization. A
sales job will then be part of the complete solution. This is
why you will hear the term "buy-in" frequently spoken of in
quality initiatives. Of course, the buy-in on the continuous
improvement effort is much easier (or, "possible") when buy-in
has been achieved for the quality initiative in the first place.
There are several books by Goldratt on the subject, and some
excellent posts by Rizzo (which he has copyrighted, so I assume
he is answering as to their availability), and Goldratt's TOC
operations have a web site.
What is Design of Experiments?
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Design of Experiments, or DOE, is the procedure that invokes
statistical knowledge to help you to
- Maximize the information gleaned from a given number of experiments.
- Minimize the number of experiments required to validate (or invalidate) an hypothesis.
What you need to take advantage of DOE principles is basically a good problem definition. A good one will include
- an agreed-upon objective
- one or more hypotheses to examine
- a selection of measurements/response variables/"Ys"
- a selection of factors/predictor variables/"Xs"
- a desired degree of certainty for everything that's uncertain when you start
Each hypothesis you will examine fall into one of two categories:
- significant differences in Ys due to selection of some X
- significant relationships between some Y and some Xs
Determining significant relationships generally involves
performing regression analysis (you might call this
"least-squares") on the data (with the number of coefficients in
the relationship depending on the number of levels an X may take
on); determining significant differences involves performing an
analysis of variance of some sort on the data.
The concerns in DOE are as follows:
- Population size. This goes to the power of the test. Too small a population can cause you to imagine a significant difference between sets of data where none exists, or to imagine no difference exists where there really is one.
- Components of variation. What should be allowed to vary in your experiment (i.e. occurs naturally)? And what shouldn't (i.e. you have to fix it or account for it)? If you have control over some component of variation, you may be called upon to use that control; if you don't, you may be called upon to block out some component of variation.
- Randomization. To remove time-varying effects from the results.
- Blocking. To remove known or suspected biases.
"Block what you can; randomize
what you cannot." -- Sir George E. P. Box
The actual design in DOE
involves using the statistical and intuitive tools at your
disposal to define the four concerns above. For instance, a
desired error rate may be used to determine a number of blocks;
a desired magnitude of discernable difference between data sets
may be used to determine population size.
If you have two sets of data, here's how to compare them to one
another:
- Check sets for normality (if they aren't all normally distributed, then you can't do the rest of this stuff until you transform the data to make them so; once they are, find the mean and standard deviation of each set).
- Perform an F-test on the standard deviations to see if they
are significantly different from one another.
- If they are, check for heteroscedasticity: are the standard deviations a function of the means? are there any outliers? You may need to recheck the way the experiment was performed if heteroscedasticity arises -- if it's not done right, or if data is recorded incorrectly, well, there's your outlier. :-)
- If they aren't, you get to "pool" the data.
- Perform an appropriate t-test on the means (meaning that the right test depends on whether the standard deviations are significantly different) to determine significant differences.
When you have more than two data sets, the procedure is
roughly the same, except
that the comparison procedure for standard deviations (Foster-Burr
test) and means (Student Newman Keuls if not pooled, 1-way ANOVA
if pooled) must take into account the multiplicity of data sets.
An "optimal" sample size for the data sets depends on
- how big an effect (i.e. difference in means) you want to detect
- how much you want to risk missing it (type I error rate)
- how much you want to risk overestimating it (type II error rate)
- how much variation you expect in your final results (pooled standard deviation).
So how many experiments to you run? If you know an "optimal"
sample size, and can run the experiment over and over for each
combination of settings for each X, then you have what is called
a factorial experiment. If instead this turns out to involve
more data taking than you can afford, then you must find a way to
"fractionalize" the factorial experiment. When you do this, you
lose some accuracy in your results. A way you can do this is to
recognize that a factorial experiment involves orthogonal arrays.
For instance: if each X has two settings, you can pretend those
settings are +1 and -1. Then, if you take the "dot product" of
the settings for any two Xs, the "dot product" is zero. Simple
example:
Two parameters, two settings each, four runs of the experiment,
dot product of settings is zero. A fractional factorial
experiment would take only part of this information, changing the
settings of more than one X at a time. For instance,
Taguchi is one expert who recommends highly
fractional factorial experiments. His orthogonal arrays
may involve a small percentage of the total repetitions involved
in a full factorial experiment, and thus would be run quickly and
for low cost. The tradeoff involved in Taguchi design is as follows:
- You lose the effects of interactions between Xs, which must be assumed not to exist.
- Taguchi assumes processes that are already under statistical control, and used in a context of continuous improvement. His design therefore assumes that, even though you can't be quite sure of the results, they're only provisional anyway.
What is Statistical
Process Control?
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Deming refers in his works to "common causes" and "special
causes."
| Deming's Causes | |
| TERM | DEFINITION |
| COMMON CAUSE | data within a normal distribution -- inherent process randomness |
| SPECIAL CAUSE | data within a shifting distribution -- "correctable" phenomena |
Special causes are generally things that you can correct for, and
are always things that you can catch in the data. Examples would
be part wear, environmental disturbances, loose fasteners,
untrained workers, impurities in materials or media, changes in
shift or suppliers, etc. etc.
You catch special causes in the data by means of control
charting. With a control chart, you're able to follow what the
data is doing in time. If a visual inspection of the control
chart causes you to be suspicious, there's a procedure to follow
that tells you whether or not you have a special cause. If you
have one, the behaviour of the special cause may help you to
diagnose what it is, or you can (with the help of everyone
involved in the process) design an experiment to help you to
isolate it. If you don't have one, then your process is said to
be under statistical control.
How to Find Special Causes
- Plot the data.
- Designate on the plot the "target value" (generally the mean).
- Compute the common-cause standard deviation (the variation
is the square of the standard deviation). This involves the following steps:
- Find the difference, or moving range, between each consecutive pair of data points you've plotted.
- Take the average of these moving ranges.
- Throw out any moving range that's more than 3.27 times the average you found in (3b).
- Repeat steps (3b) and (3c) with the moving ranges that are left, until you only have moving ranges which are not greater than 3.27 times their average.
- Once (3d) is done, your common-cause standard deviation (which we'll call S_cc) is the resulting average moving range divided by 1.128.
Your process is under statistical control if your common-cause standard deviation is close to zero. - Plot "control lines" horizontally for mean plus or minus 1, 2, and 3 times S_cc. (Don't forget to label 'em.)
- The mean has shifted significantly, and your process has gone
out of statistical control, if any of these rules of thumb are
violated:
- one point outside 3S_cc on either side of the mean
- two-out-of-three consecutive points outside 2S_cc on the same side of the mean
- four-out-of-five consecutive points outside S_cc on the same side of the mean
- eight consecutive points on the same side of the mean
On your chart, make sure to mark the following, because you may need it to diagnose special causes:
- mean and standard deviation of all data
- S_cc
- the number of data points
- the source of the data
- the contact info
- the date, time, and duration of charting
What is Just-in-Time?
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Just-in-Time (JIT) is an inventory procedure that primarily
involves bringing spare parts to the assembly line (or to the
loading dock for delivery) only when they are needed, and
minimizing in-house spares. Reid describes in his book the
advantages seen by Harley-Davidson in adopting the JIT
philosophy:
- Reduces setup time
- moves some steps in setup "off-line," thus reducing delays
- eliminates unnecessary movement
- eliminates some nuts and bolts at the work station
- eliminates some machine-based adjustments
- standardizes tooling, dies, fixtures, part design and specs
- uses block gauges and templates for adjustments
In short, because the spare parts aren't going to be there, the parts coming through pretty much have to be right and the machines pretty much ready to accommodate them. - Focuses the flow of the process
Instead of having all the machines of a given function in the same physical location, the production lines have functions flowing in series. One station's output goes on to the next station, which is next in line. - Encourages containerization and parts control
- Encourages operator preventive maintenance
The JIT system, where it is seen as useful, can be set up in three phases: first, examine the "little things" that can be done to save time; second, examine minor modifications of tools, dies, fixtures, machines and procedures; third (after you've saved as much $$ as you can :-)) look at larger capital expenses for new machinery. Again, don't buy the machinery until you've made improvements to your process without the expense. Otherwise the expense won't help as much. Maybe not at all.
What do I need to know about Total
Quality Management?
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What we know today as Total Quality Management may well vary from
organization to organization, and may also depend on which
consultant is teaching TQM to the organization. For this reason,
we will ignore most of the management BS that seems to accompany
quality initiatives and concentrate on the fundamentals.
Why TQM is not held in universal esteem:
- TQM is often active in organizations that are
- TQM is identified with excessive documentation. Excessive, boring, irrelevant documentation, couched in "psycho-babble."
- TQM is identified with consultants that teach concepts to an audience they do not know, in an industry they do not understand.
- TQM is identified with managers who make a formal process out of the least common denominator of sound day-to-day work practices, and impose it on their entire workforce in a "one-size-fits-all" fashion.
- TQM is identified as a way of telling highly skilled professionals that their work is not good enough, and that they must work harder, sometimes doing things totally unrelated to their previous tasks, to be competitive.
With all these negative pictures being conjured up in the
worker's mind, it's understandable that there would be opposition
to a quality initiative -- even if the initiative is based on
sound understanding. So many people have these pictures in mind
-- so many have been burned by quality initiatives -- that it
can't be their fault they have them.
How TQM comes to be thought of this way:
- Quality initiatives built on sound principles still contain ingredients that arouse suspicion. Buzzwords like "profound knowledge," "team-building," and so forth. They sound like they contain "soft" elements.
- The more scientific aspects of TQM are not second nature to us, or to those who impose TQM on us, or who teach it to us. Teachers will sometimes revert to those topics that are easy to teach.
- We assumed that the quality initiative was designed to replace dependence on competence.
- We assumed that even the most basic, elementary operations were looked at as candidates for improvement, sometimes equally to complex processes.
- Previous bullshit quality initiatives have left us jaded.
Where we are without organizational attention paid to continuous improvement:
- Depending on inspection to "inspect in quality." Inspection in and of itself cannot put quality into a system -- it can only reject what fails to meet the standards.
- Working with an unchanged product, because to change it we must work differently.
- Missing the connection between statistical variance and corporate bottom line.
- Fixing only what's broken, and only after we hear it break.
- Depending on behavior that, even in masters of their craft, has an element of randomness.
- Specifying tolerances outside of product and process knowledge and customer understanding.
- Determining process improvements via full factorial trial and error.
- Seeing new initiatives as extraneous to our real work.
- Always hoping our work environment will be like a Skunk Works, except that we will be individually respected as well. (Since Kelly Johnson respected almost no-one. :-))
What could we really do instead?
- Introduce the scientific aspects of quality (SPC, DOE,
TOC) to everyone in the organization
- without adding new worker requirements (though some present ones may be changed)
- without "talking down" to anyone, and without reduction to the "least common denominator"
- and with the "big picture" always in the background.
- Enable all workers to contribute to the improvement of
the process they are obligated to work under
- process improvement must be shown as part of our work, not something that keeps us from getting our work done
- "losses" must be defined for all to understand -- both those intrinsic to the product's function and those due to variances
- training must be made available that enables workers at all levels to continue to "do things right" as the processes are made to change
- Modify the role of inspectors
- give them the ability and authority to fix problems
- make them responsible for SPC charting
- reward them on the basis of working with processes to improve them, and on the impact of those improvements on the bottom line
- allow them to address the needs of new markets
- Cease and desist immediately the practice of all
bullshit
- concentration on trivial problems (e.g. charters)
- emphasis on slogans
- insistence on management tools for non-management personnel
Deming, in The New Economics, points out a few fundamentals for managers, based on the idea that understanding of the way a system works includes understanding of the way people work. No improvement of any system can be undertaken outside of improvement of the management of people.
- Individual performance is largely a function of the system the individual works in. The system is the responsibility of management. Every manager (at least of engineers) should review Deming's "red bead experiment" before embarking on performance appraisals.
- Fear will cause engineers, inspectors, and lower-ranking supervisors to "fudge" numbers in order to prevent unjust punishment. Likewise, performance measures based on sales, revenue or costs will lead to another type of number-fudging, and to dishonest customer relations. Psychology and variation are thus locked together.
- Once the numbers have been fudged, predictions and decisions based on them are fundamentally flawed. If management therefore wants the truth, it must drive out fear.
- Don't tighten tolerances first. If the process is already out of statistical control, tightening tolerances will make the process more expensive without making it better. Likewise, if you crack down on people, you make them unhappy without making them better.
Here is a brief description of the Red Bead Experiment. Choose
several "operators" at random. Give each a sifting box. Each is
to take a sample of beads from a larger box, one which contains
mostly white, but also red beads. The samples are to be sifted
until there are just enough beads to fill each slot in the
sifting box. The red beads are counted. Those with the most red
beads are the "best performers." Deming makes the point (absurd,
but truth is stranger than fiction) that real-life processes can
tend to be only slightly less random than the drawing of beads
from a box.
Here is another experiment that illustrates a similar idea. Hold
a funnel over a target on a table. Then cause a ball to fall
through the funnel toward the target. Miss the bulls-eye? Too
bad. Have to have management intervention. Move the funnel from
its previous position to compensate for the error. Try again.
Miss the target again? Management intervention again. Before
long, you have all sorts of scatter in the points where the ball
hits. Solution? For the time being, ignore the target and try
to achieve uniformity. Hold the funnel in the same place over
and over and plot the scatter. Once the scatter is
stable, then you can make adjustments.
Overmanagement is perhaps the biggest impediment to quality.
Adler points toward a modern misrepresentation of the
time-and-motion-study ideas of Frederick W. Taylor:
- Routine, repetitive tasks require standardized procedures.
- Standardization reduces motivation and creativity.
- Lack of motivation leads to dysfunctional employee behaviour.
- Counterproductive behaviour leads to more authoritarian management.
- Micromanagement leads to more routine, repetitive tasks.
This is what we see, and why Adams makes so much money writing
"Dilbert" books. :-) The reason the picture is incorrect is
because the second step above is misapplied. Taylor didn't
recommend it. Business evolved into it -- by having formal work
standards imposed on employees, instead of designed by employees. A switch from the one to the other can reverse a situation that's going down the plughole.
Effective Teams
A lack of understanding of effective teamwork is an
impediment to quality.
There are five ingredients in most effective teams:
- purpose
- leadership
- membership
- interaction
- deliverables
It appears that each is necessary, but none are sufficient
without all the others.
Purpose. You would
suppose that a team is formed precisely because of a purpose.
(You would suppose that, but I at least have seen other things
happen. :-)) The effective team's purpose has the following
qualities:
- Based on organizational need
- Founded according to sound, reasonable principles
- Tied into the self-interest of the team members, thus making it easier to sell to them
- Faced with a competitive imperative
Leadership. The team leader is not to be confused with line management, even when the line manager is the team leader. (In that case, it's necessary for the leader to wear a different hat.) The effective team's leader has the following attributes:
- Willingness to work to achieve (and maintain) "buy-in," to build confidence
- Willingness to make decisions based on team findings, rather than solely on personal judgment
- Willingness to let experts be experts, and to manage work rather than do it
- Ability to grant or obtain authority for members to carry out decisions
- Ability to grant incentives for team members to make one another "look good"
- Understanding of the skills and behavior of the team members
Membership. If the team members have to be drafted, then the purpose of the team should probably be reexamined. So for this aspect of the effective team, we assume "buy-in" has been achieved -- that the members start with commitment to the purpose. (Some teams are partly founded on religious fervor. It was unclear to me from this discussion whether a religious conversion to the team's purpose is necessary.) To achieve the rest of what the membership needs, it is quite possible in some cases that training will be necessary:
- Mutual respect
- Reliance on one another to be willing and able to do their jobs
- Common, confident view of group objectives
- Freedom to raise questions and criticism
Interaction. The term "trust" was raised again and again in this discussion, and it became clear that in the context, "trust" didn't mean "with our family secrets." It meant recognition of professional responsibility and reliance on having said responsibility fulfilled. Having established trust in this sense, interaction is based on this trust in the day-to-day functioning of the team:
- Protection of one another's self-esteem
- Soft-pedaling our natural tendencies to cover our asses
- Setting aside of all preconceived notions of how things (other than fundamental engineering principles) are "to be done," of natural resistance to change
- Responsibility for our own actions and group-assigned tasks
Deliverables. The obvious
deliverable is the fulfillment of the group's purpose, if it can
be fulfilled; and some detail as to why not otherwise. (Some in this discussion felt that a truly effective team could not fail to fulfill
a truly worthy purpose.) Not so obvious is the deliverable of "lessons
learned." There are two kinds of those: the group kind, that should be
documented in plain "English" (or, written clearly in whatever your
language happens to be); and the individual kind, to be filed away in
our memories to be drawn on (or recorded on resumes) later.
Rewards. Individual performance
evaluations and rewards are simply inconsistent with team performance,
particularly if the individual is on the team full-time, and may even
undermine the team. (Deming was one author who showed why individual
performance evaluations tend to be tied into random chance anyway.)
Most participants in this discussion felt that rewards should be tied
into team performance, and shared nearly equally among members (some
suggested peer evaluations could be used to determine MVPs if appropriate),
and might well be used as a "carrot" to help achieve "buy-in." Confidence
is, after all, tied into the employee's self-interest, and there's more
than one way self-interest is expressed. :-)
Personality Types
Recognizing what personality types make up your team can go a long
way toward helping you predict what contributions each member can make.
| Partial Myers-Briggs List of Personality Types | |
| TYPE | CHARACTERISTICS |
| Sociability: Extroverts |
|
| Sensitivity: Intuitive |
|
| Perceptivity: Perceiving |
|
| Intellect: Feeling |
|
This list is VERY incomplete. A Myers-Briggs test would place
you in one of 16 different categories, depending on which of
two ways you fall in the Intellect, Perceptivity, Sensitivity,
and Sociability classes. There is a Web site below that goes
into a bit more detail, and a host of information out there on
Myers-Briggs testing. The bottom line is that companies will
take test results from Myers-Briggs for their employees, and
try to take those results into account when forming working
teams. (Of course, you need a critical mass of players to make
that process work.)
Group Responsibilities
- Individuals master project knowledge for themselves; then help others on the team master that knowledge too.
- Ensure no undue stress placed on any member.
- Maintain a shared vision.
- Maintain cooperative involvement in team meetings.
- Allow for free information flow. The team leader should work with the others to ensure that the team has an information model.
- Prioritize the quality of ideas over the talent, resources, and influence of any individual member.
- Balance risk and reward, and try to achieve consensus on what the balance is.
Leader's Responsibilities
- Choose members carefully, offering them the group responsibilities given above.
- Consider temperament and personality type as a qualification.
- Make sure team goals are clearly defined; get "buy-in" at the start.
- Allow free expression of ideas when ideas are actually needed; make sure everybody is comfortable in the group even when ideas aren't needed.
What is Quality Assurance?
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A quality assurance system is needed to help ensure that the proper
materials of construction are used, that fabrication and inspection
procedures are proper, and that installation procedures recognize field installation concerns. The quality assurance program is an
essential part of the mechanical integrity program and will help
to maintain the primary and secondary lines of defense that have been designed into the process to prevent unwanted chemical releases or
those which control or mitigate a release. 'As built' drawings,
together with certifications of coded vessels and other equipment, and materials of construction need to be verified and retained in the
quality assurance documentation.
-- from OSHA 1910.119, "Process Safety of Highly Hazardous Chemicals"
This may be hard to believe, but much of quality assurance (or, QA)
involves reading and writing. That's because improving quality can
involve analysis of behavior -- something that's neither numerically
quantifiable nor consistent. Although control charts are critical to
SPC, they're not the whole story in a quality assurance program.
(NOTE: some programs don't take quantifiable data into account at
all. Beware!)
A QA system will ask the following questions:
- How do we do things now?
- How do we SAY we do things now? What requirements do we have in place?
- Where do the first two answers deviate?
- How do we fix the deviations?
...and perform the following actions:
- Fix the deviations.
- Document the way things are done according to standards.
- Get "buy-in" from everyone involved.
- Adopt a policy of continuous improvement which includes auditing these processes.
ISO 900x is an international standard that helps companies align
the way they do things with the way they say they do things. A QA
system that conforms to ISO 900x has procedures for reporting and correcting problems. This doesn't guarantee product quality, but
it provides a framework for conscientious companies to pursue
continuous improvement.
Event Reporting
As part of a QA system, you'll analyze a report of an event. Maybe
a control chart reveals a process has fallen out of statistical
control. Maybe there's been a failure in a part or machine. Maybe a
new module has been written for a legacy software program. These are
events, and witnesses or participants will be called on to contribute
to the report. If you have to prepare the report, you may need to interview those involved. Even if you don't have to prepare the
report, you certainly must read it to become familiar with the event.
When you've become familiar with the report, then you can analyze the
event and all behavior leading up to it. You have to be able to visualize
what each person involved (or, "actor") did. This means you may have to
- mark up the report
- clarify the identities of multiple actors
- match up each action with a single actor
- infer actions that aren't stated explicitly, such as
- when the narrative is written in passive voice
- when there's been a change in process state
- when some action is assumed in the narration (e.g. estimated data -- but whose estimate?)
- place the actions in context
- organize the actions in such a way as to avoid creating conclusions (e.g. with "did" format instead of "did not")
With all the actions in context, you can make value judgments on each. The judgments can resolve
- whether more data is needed by the actor
- whether measurements or estimates taken at that moment could be considered reliable
- whether the narration was at that moment reliable
Anything that's left after those judgments are made is probably a deviation
in the process -- one that you alone can't fix. But that's what you're there
to identify!
Software QA
Software QA is analogous to the process above in that you want to
know what each method does, when it does it, and on what variables
it does it. A computer program must supply an answer for all possible instances within its scope, and those answers must be correct and
reasonable, before its results can be released to a customer. Then
you "lock down" the program, give it a version number, and provide documentation as needed.
The QA role is to keep a program from being updated and used without
everyone concerned knowing what the update IS and therefore not using
it the same way. It's a function that sometimes must be performed pretty much concurrently with the actual collection of results for
the customer, unless you're selling the software as a consumer product.
Customer requirements dictate how the program is to be tested.
As is the case with any consumer product, there is a difference in
"generation quality." That difference can be significant. Software
will (hopefully) improve with successive generations, as will most consumer products. But a "bootleg" product (for instance)
will deteriorate with successive generations.
Sample Quality Assurance Review
Written by the Editor while working for start-up GreyPilgrim Inc.
I have completed a review of [company name's] QA document, and as
a result feel comfortable with collecting information that we need
to prepare a similar document of our own. I understand the need for such a document: we want our customers to feel that we can build
repeatedly to their specs. (Or, if they don't give us specs, to specs
that we generate from their requirements.)
Here I will summarize what I think is directly adaptable to our needs
from the [company name] document, and what I think will make our
document even better. It may not be necessary to have a better document, but I think we have to take a different approach than theirs for the
following reasons:
They don't really define "quality," and I think this is because the
term changes meaning depending on the product and the customer. I
believe we can and should define the term, and with enough meat that our customers know we have direction.
There are certain scientific aspects of quality for which everyone on
the team should have a basic knowledge. This is because in so knowing
we'd all be on the same page, and everyone on the team bears some
responsibility for the quality of the product. This is necessarily
different from what [company name] is doing: [company name] is a big
company and has a dedicated QA department, along with other functional
departments that we just can't have for a couple growing years or so.
[company name] does train "all personnel performing activities affecting
quality," and tests them, but my experience tells me that much of what
these folks are learning is either (a) disconnected from the job they
actually do, or (b) too simple to change their approach to their work,
or both. We can't afford the same approach.
Because (I assume) [company name] has a more diversified product line,
or at least more customers, than we do, they give few specifics about
how their QA system is applied to a job. (Where they do give specific
instructions, those instructions are generally excellent -- but they're
buried in the document more often than not.)
[company name]'s entire QA program is centered around inspection. (In
fairness, this may be because inspection is the only way to judge
compliance on certain items. But for whatever reason, the document reflects this focus.) We can't do this, because you cannot inspect
quality into a product. All inspection will do is reject noncomforming
parts -- it doesn't improve the processes or those who carry them out.
[company name] also gives the inspection responsibilities to separate
individuals (which IMPO is good) who have no direct ownership of the
process (which IMPO is dubious) and who have no direct powers to change
it (which IMPO is bad).
Individual roles are unclear. You will have individuals whose only role
in the process is to receive a document, date-stamp it, and route it to
someone else. You will have other individuals who have heavy responsibility
but where they come from is unidentified. And the document is about
responsibility: who takes the fall if a product fails. We need to be about
responsibility in a different way: who really *needs* to support each aspect
of the process. Since quality is the responsibility of each of us, we must
all take the fall in event of a failure.
Here's what [company name] considers important considerations in inspection
of a given component:
- Consequences of failure.
- Uniqueness & complexity of design or fabrication.
- Special control or observation of processes or equipment.
- Ability to demonstrate compliance via inspection or test.
- Quality history and degree of standardization.
- Difficulty in repair or replacement.
Throughout this document, [company name] refers to reviews. Preliminary
and Critical Design Reviews, from which formal changes in design can be
formally requested. This is a common way of doing business, which if
adopted shows we can speak the same language.
Throughout this document, [company name] refers to identification and
traceability. We've not been particularly good at keeping records up to
this point, primarily because we have so much crap that there's no time.
But it's a good idea to adopt specs on these things, like [company name]
does:
- Which records really need to be maintained.
- Part numbers and characteristics.
- Restrictions on where and how documents and parts can be marked.
- Traceability from parts to associated documentation.
- Review and approval cycles.
- Storage, handling, and shipping.
- How to handle noncompliance.
They actually have a "Quality Plan," though they bury it under "Inspection Planning." Which is another way of saying they are trying to inspect in quality, and again I say unto you: thou shalt not. But the plan is interesting, because all this stuff is identified:
- Relevant drawings, part lists, and specs.
- Technical drawings and documents requiring review and approval, and by whom.
- Inspections needed, and by whom, and by what methods, and at what points in each process.
- Specific identification and traceability requirements.
- Detailed requirements for regular process control and observation, equipment condition, and personnel qualifications and training.
- Required sampling procedures (if sampling is needed).
- Documentation as evidence of quality compliance.
Their argument is that all this stuff must be in place before a part is shipped,
and we are going to have to head in this direction as well.
Definition of Quality
Here is what I think will pass as a start for a definition of quality
for our purposes:
The extent to which a product meets
requirements agreed upon by ourselves and our customers.
Nothing this simple is stated in the [company name] document, yet if you
ask around in industry you will find that a common problem in quality
initiatives is having such terms undefined.
Once we define this term (whether by the above definition or some other),
we have some idea where to go next. The above definition suggests that we
reach an agreement with a customer over requirements. Then we work on
component specs to fit into the requirements. These things are pretty
much what we are doing now. But the component specs then suggest what
we must do to verify compliance with specs. As you know, there are five
ways to verify compliance:
- analysis
- demonstration
- inspection
- similarity
- test
We have to date relied on demonstration and test. This is not surprising
because we are trying to sell a system, not its components, and because
our systems have tended to be one-of-a-kind. We are now moving away from
one-of-a-kind systems, and that opens up to us the other three means of
verification. Even so, we are not headed toward a situation in which
inspection should be our most common means of verification. We are,
however, headed toward a situation where we must start inspecting, which
means we have to agree in advance on the how, why, and who.
We also have to agree on what constitutes compliance, and what constitutes
satisfactory test or inspection results. That's something we would probably
do as a management team early in the job, but we wouldn't document the meeting.
What is ISO 9000?
Return to Contents
There are a fair number of sites out there that talk about ISO 9000.
Here's the summary: ISO 9000 and subsequent numbers are certifications
for a documentation system. The certification says that you have a
quality system in place in your company, one which addresses the following:
- people
- work
- activities
- tasks
- records
- documents
- forms
- resources
- rules
- regulations
- reports
- materials
- supplies
- tools
- equipment
...in short, what makes up processes. The certification process verifies
that you HAVE a quality system, and that you have it DOCUMENTED. That you
actually do what the documents SAY you do. BUT... it does nothing whatsoever
to ensure continuous improvement of quality in products or services. That's still up to you.
Nevertheless, many potential customers, including the US Government, place
a high value on the certification. It's not to be overlooked.
References and Resources
- Deming, W. E. Out of the Crisis (Editor's Choice)
- Goldratt, E. M. The Goal. ISBN 0-884-27061-0
- Goldratt, E. M. It's Not Luck. ISBN 0-884-27115-3
- Goldratt, E. M. The Haystack Syndrome. ISBN 0-884-27089-0
- Goldratt, E. M. Theory of Constraints. ISBN 0-884-27085-8
- The Goldratt Institute
- The PD Institute
- Brainstorming
- "The Memory Jogger." Methuen, MA: Goal/QPC, 1988.
- Brainstorming 101 shareware
- www.brainstorming.co.uk
- Brown, Hitchcock and Willard. Why TQM Fails. Burr Ridge, IL: Irwin Professional Publishing, 1994. ISBN 0-786-30140-6
- Starline Software Ltd. "CATALYST EventAnalyzer."
- Supply Chain Solutions. "SCS Case Studies."
- whatis.com. Definitions -- quality assurance.
- OSHA 1910.119, "Process Safety of Highly Hazardous Chemicals."
- Johnson, R., D. Johnson, and K. Smith. "Cooperative Learning: An Active Learning Strategy for the College Classroom." Baylor Educator, Winter 1990.
- Robinson, S. "Build highly effective teams with personality testing." TechRepublic, 10.30.2002
- Deming references at Clemson
- Deming references at MIT
- OMatrix shareware
- MicroConsultants shareware
- ISO
Authors
Ron Graham (Editor)
Lisa Henn
Greg Locock
Tony Rizzo


