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Fixing Production Mistakes
Source: Managing
a Small Business
This guide is intended for small manufacturers and
deals with the essential issues and steps that should be considered by a manufacturer when
a production mistake has been found. A production error is analyzed in check-list form to
establish its extent and its effect on the product and the production line and the steps
needed for corrective action that integrates the "fix" into the existing
production systems and schedules.
What Will You Do?
What would you do if several or several hundred production units manufactured in your
plant were found to incorporate a defective or improperly installed component? Assume the
logical complication that the defective units had been distributed to numerous work
stations along the production line to be fitted into higher assemblies. Add to this the
grim fact that defective end items had been shipped from your plant and were now in the
transportation pipeline, at your dealers, and in the hands of consumers.
Production errors are not unique. To the contrary, they are chronic. They cost industry
hundreds of millions of dollars each year, and they waste resources that are becoming
increasingly scarce. When you, the manufacturer make a production mistake, we all lose.
The ultimate frustration occurs when managers and their people are not sure what needs to
be done to correct the problem. When the corrective action process is unorganized or in
disarray, the drain on resources is enormous and unpredictable. The ultimate cost of the
fix soars.
Mistakes are a challenge to a good manager's sense of order. Correction is vital to the
survival of the company. Actions need to be taken and controlled to reestablish quality
production.
The following questions are far from all inclusive. Each product and plant has its own
characteristics, and fixing a production mistake would, of necessity, need to be tailored
to both. However, the questions and the outline of a corrective action plan should
stimulate your thinking and help you to organize your people and resources should you be
confronted with a production mistake.
Analysis
1. Do you know the exact physical nature of the mistake?
Did a part break?
Was a circuit incomplete?
Was an incorrect material used?
Do you know what happened?
2. Have you examined physical evidence of the mistake?
Will a personal examination of the mistake by you help you to understand the problem
better?
3. Do you know where in the plant the mistake actually occurred?
Have you pinpointed and brought to the attention of management the specific work unit
and work station where the error was first noticed?
Did you track back along the production line to the work station and worker where the
mistake was being made?
Did you track the mistake forward along the production system to ascertain the extent
to which the fault was included in higher assemblies and end items?
4. Did you stop the work step that was creating the mistake?
5. Did you identify the people, skills, materials, tools and equipment, data or work
practices that caused the mistake?
Do you know which were directly responsible?
Do you know which were indirect contributors?
Do you know how they became part of the approved production process?
6. Must you correct the mistake on finished items or on items on which rework would
be economically or technologically unprofitable or impractical? In answering this
question, have you considered:
Safe use of the final product by the ultimate consumer?
Established quality standards?
The effect on service life?
Maintainability of the part during normal operations?
The effect on the cost of operating the end item?
Other significant characteristics included in the specifications?
7. If the error will not cause significant deviations from drawings or
specifications, should you review the situation with the ordering agencies or companies
before taking any further action on those items that now incorporate the defect?
8. Should you impose a work stoppage?
Do you know what the effects of a work stoppage will be on:
Your production line?
Your contractual commitments?
Do you have alternate workloads that can be readily injected into the gaps until a
corrective action decision for the mistake can be implemented?
9. Have parts, assemblies or end items, incorporating the error, been shipped from
your plant? If they have:
Have you estimated the effects of the mistake on the market place?
Have you estimated the effects of a decision to recall the defective items from your
customers, dealers or consumers?
Are trucks or freight cars now being loaded by your shipping department with items that
contain the production error?
Should the shipments be off-loaded?
Have you issued instructions to cover the situation?
Have you confirmed that your instructions were complied with?
Do you know the effect of the stop shipment order on the customers scheduled to receive
the items?
Do they have sufficient stocks on hand that do not contain the mistake to tide them
over the rework period?
Can you identify all shipments of the items that have the production error, by
customers' identity, shipping order number, item serial numbers, method/date/time of
shipment, and any other means of identification that will assist your customers to locate
the faulty items and segregate them from usable stocks in their warehouses, dealers
shelves or in actual use?
10. Based on your analysis to this point, should the recipients of items containing
the production error be notified?
If notification is to be made, have you issued the required instructions, including the
recording of the means of notification, date/time/method, and the names of the persons
initiating the contract and receiving the message.
Are you certain the message was received by the customer and understood?
If you have imposed a work stoppage on the production line, and stopped further
shipments of the items, do you know your shipping commitments for the next 24 hours, 48
hours, 72 hours?
Should the recipients of the shipping commitments in (the preceding question) be
notified of the delay in shipping and given a new shipping date?
11. If the faulty items are to be recalled to the plant, can shipments in the
pipeline be diverted back?
If they can be, have you arranged for temporary storage space?
As an alternative to recalling the items back to the plant, can the shipments be
completed and arrangements made with your customers for the rework, either by doing it
themselves or by contracting out?
As another alternative, can you send technicians from your plant to your customers
facility to fix the error?
Have you examined the alternatives to correct defective items that were shipped and
arrived at the most logical and practicable course of action considering your customer's
needs, the time factors involved, the economics of the situation, and your reputation?
Do you know what the effects will be of your decision to fix or not to fix?
Taking Action
1. If the mistake is to be fixed, do you know what needs to be done to develop the
corrective action and put it into effect?
2. Have you considered the demands that will be made on and the availability of:
Plant facilities (structural and environmental) Finances?
Energy sources?
Communications systems?
Transportation?
Public relations and Marketing?
Shop equipment?
Materials?
Supplies?
Tools?
Data?
People (skills, training, safety, workhours, etc.)?
Other services?
3. Can the faulty items be processed economically for teardown to get at the error
and then re-injected into your routine production system without disrupting the production
flow?
If not, do you need a special, one-time production group to do the teardown, repair and
reasembly job?
If, after teardown, the parts can be re-injected into routine production, have you
identified the points along the production system where each identifiable part or partial
assembly can be inserted?
4. Have you identified all the work units and work stations that will be directly
affected by the rework of the faulty items and the corrective action in general?
Do you know how they will be affected?
Do the supervisors and direct workers of those work units and at those work stations
understand the problem and what is expected of them?
Have you ascertained which work units or work stations can be by-passed during the fix
to minimize disruption to normal production and reduce the ultimate cost impact?
5. Will the fix make it necessary to:
Realign work space?
Move shop equipment?
Modify tools and equipment
Fabricate jigs and special holding devices?
Redesign parts?
Revise procedures?
Change standards?
Retrain people?
Reschedule and Reprogram?
Modify contracts with customers?
6. Can the corrective action taken as a result of finding this error be applied to
future designs, management practices and production system improvements anywhere else in
the plant?
Has this experience given you ideas to improve your operations?
General Characteristics of a Corrective Action Plan
A corrective action should be planned out and integrated into your production control
system, which could be Gantt Charting (a bar chart) or the Critical Path Method (a graphic
model). Both systems aid production planning and scheduling by setting up time schedules
for starting and finishing various tasks on one or many items. Your corrective action plan
form requires careful completion according to the following nine steps:
1) Problem: A concise statement of the problem. References can be included to
identify other documents giving more detailed information.
2) Work Unit (Prime): The title or other identifying symbol of the shop, unit or
group where the cause of the problem exists and where the action will be taken. A mistake
may be quite extensive and the effects fragmented and widespread. Actions may be needed by
several work units. A sub-plan may be appropriate for the different work units, functions
or locations.
3) Work Unit (Associated): The prime work unit usually needs help from other
units. It may be useful to identify these supporting units, their supervisors and
telephone numbers. It can save time for those directly involved in the action.
4) Date: The date the plan was approved can provide a valuable control device.
The plan may need to be revised to include additional steps, delete certain actions, or
change procedures even as the action proceeds. The DATE plus a note that the sheet
supersedes one of a prior DATE is the control.
The next three Blocks represent the Task Breakdown. It may be more logical to break the
actions down by work station; worker in some situations; in other cases the
"Start/Completion Date" may be the most important factor in sequencing the
steps. Circumstances may dictate that accessibility to certain parts on the assembly
compels the sequence. Each situation and set of circumstances would need to be analyzed in
detail to arrange the best sequence.
5) Work Station/Responsible Worker: Who does what, and in what sequence? The
station and worker should he in the WORK UNIT identified at the top of the page.
6) Operations: To the most practicable extent this space should state the
specific actions that needed to be taken-sequentially if possible. Generalizations should
he avoided as they might be subjected to varying interpretations and lead to confusion.
This should not be the place to say why the mistake happened or otherwise analyze the
problem. This space should confine itself to do-this type instructions. It should be of
DIRECT use to the worker doing the job.
7) Starting /Completion Dates: The dates should be realistic, otherwise, a work
stoppage could occur. The dates should consider such diverse factors as the availability
of tools and equipment, test sets, raw materials, energy, skills, workhours and work
shifts. It could consider whether or not the dates would be compatible with normal
production operations. If new design or fabrication techniques are to be applied, the
starting dates could be affected accordingly. A START and COMPLETION date would ordinarily
be required for each entry under OPERATIONS.
8) Follow-Up Date: Follow-up is an option of management to assure that the
action was taken and was adequate. It could include examining the product, checking
documentation or interviews with the people doing the work. It assures the manager that
the job was done, and done right.
9) Confirm Permanent Correction: After the crisis has passed, management may
wish to take that extra step that would prevent the mistake from recurring. What really
caused the problem? What should be done about it? Is a permanent change needed in tools,
equipment or materials? Should the shop layout be changed? Do workers need additional
training? What about quality control and product inspection procedures? The fact that a
mistake occurred in one unit could mean that it might happen in another. The mistake that
was corrected could provide an opportunity for a significant technical or management
improvement throughout the plant. |