tqm case decfab inc
TRANSCRIPT
8/2/2019 Tqm Case Decfab Inc.
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1. Develop a Pareto diagram for the Problem solving team that describes the major
causes of the problems with the production process of the dental drill.
The Pareto Diagram is effective to understand the major causes of problem and
their occurrence frequency. In the above Diagram it is identified that the major
problem on the production line is Poor Machining and its frequency is 58 out of
110 which 53%. The Decfab has the opportunity to improve its quality by solving
poor machining problem.
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2. Develop a histogram for the team of the diameter frequency data for the dental
drill production process.
The Histogram is effective to understand the major causes of problem and their
occurrence frequency. In the above Diagram it is identified that the major problem
on the production line is Poor Machining and its frequency is 58 and second
major cause of problem is Bad Incoming Part.
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3. Develop a P-chart using three standard deviations to help Mr. Hanson determine
if the quality of incoming parts from the Ajax Company are poor or not.
The quality of incoming parts from the Ajax Company are poor because out of 12
samples 1 sample is out of the UCL also the variation among the UCL and LCL is
very high due to high variation in the poor quality parts imported from Ajax
Company.
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4. What does the P-chart tell you about the incoming parts from the Ajax
Company?
P Chart tells that incoming parts from Ajax company has very poor quality, out of
12 samples, observation 7 has 24 poor quality part from 2500 parts so observation
7 is outlier and it fall outside the control limits. In this instance, the process is out
of control.
The continuous change in the poor quality parts with high density indicates that the
production line of Ajax Company is not following good quality control over the
Production.
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5. Develop X-bar and R charts for the screw data from the Delta Machining
Company, using historical process information to determine the center lines.
The above chart shows that out of the sample data given about the screw from the
delta company none of the points fall outside the control limits UCL or LCL, so on
the basis of the observations taken it can be said that the process is in control and
there are no rejections.
X Double Bar = ∑ X BAR/ n = 0.54
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The above chart shows that out of the sample data given about the screw from the
delta company none of the points fall outside the control limits UCL or LCL, so on
the basis of the samples it can be said that the process is in control and there are no
rejections.
R BAR = ∑ R/ n = 0.211
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6. Does DecFab have a problem with the screw part from the Delta Machining
Company? If so, why? If not, why not?
No, The screw parts from the Delta Machining Company do not have any major problem can be said on the basis of the X BAR Chart where the samples are in
between the UCL and LCL also the variation of screw diameters is very low.
The screw parts from the Delta Machining Company do not have any major
problem can be said on the basis of the R BAR Chart where the samples are in
between the UCL and LCL but the variation of screw diameters is little high which
can be reduce for better quality Product.
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7. What is the failure rate for the dental drill, based on the reliability testing?
Failure rate = Number of failures
Number of units tested
Here, number of failures = 3 and number tested = 6
So, Failure rate = 3/6
= 0.5 or 50 %.
The 50% failure rate indicate that the Dental Drill product of Decfab Company is
not working up to the good quality marks which is one major cause of decline in
sales and quality issues in the Company.
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8. What is the mean time between failures (MTBF) for the dental drill?
Mean time between failures or MTBF = 1/FRn
Where,FRn = Number of failures
Operating Time
Total time of the operation = 100 hours * 6 units
= 600 unit hours.
Non-operating time = 3*15 i.e. 45 hours for the 1st unit
+ 3*50 i.e. 150 hours forthe 2nd unit
+ 3*85 i.e. 255 hours for the 3rd
unit
= 450 unit hours.
Operating time = Total time – Non-operating time
= 600 – 450
= 150 unit hours.
Thus, FRn = 3/150
= 0.02 failure per unit hour.
So,MTBF or Mean time between failures = 1/FRn
= 1/0.02
= 50 hours.
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9. What is the inherent availability of the dental drill for the dentist?
Inherent availability = Uptime/ (Uptime + Downtime)
Total Time = 600 hours
Uptime = 450 hours
Downtime = Total time – Uptime
= 600-450 hours
= 150 hours
Inherent availability = 450/ (450+150)
= 450/600
= 0.75
The inherent availability of the dental drill for the dentist is 0.75 or 75%.
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10. Does DecFab have a problem with the dental drill wearing out prematurely? If
so, why? If not, why not?
Yes, The Decfab Inc. have problem with the dental drill wearing out prematurely
as 3 out of 6 samples fail during the test which is 50% of sample.
The mean time between failure rate is 50 hours, where the units was designed to
work for minimum of 200 hours and tested for 100 hours.
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11. Develop and draw an Operating Characteristic (OC) curve for Mr. Hanson to
help with his sampling plan. Assume n=15 and c=0. Find the probability of
acceptance (Pa) for p (% nonconforming) of 1, 5, 10, 15, 20, 25, and 30 percent.
The Operating Characteristic Curve is useful to analyses the probability of
acceptance of a lot with respond to the defective percent. In the above graph it can
be said that the probability of getting accepted the lot is 0.8601 when the defect is
1% which reduces up to 0.0047 when defect is 30%.
It states that even a bad lot have the probability of getting accepted 0.0047 where a
good lot rejected 0.1399 (1-0.8601).
NOTE:- The probability values are taken from the Binomial Probabilities Table
where n = 15, c = 0.
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12. Determine the producer’s risk, “a” and the consumer’s risk “b”, if AQL=5%
and LTPD=10%
Producer Risk = n! pr qn-r
r!(n-r)!
= 15! (0.050) (0.9515-0)
0!(15-0)!
= 0.4633
= 1 – 0.4633
= 0.5367
The risk of Producer is 0.5367 at 0 defects.
Consumer Risk = n! pr qn-r
r!(n-r)!
= 15! (0.050) (0.9515-0)
0!(15-0)!
= 0.4633
The risk of Consumer is 0.4633 at 0 defects.
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13. Determine the Average Outgoing Quality Limit (AOQL) for the above
sampling plan.
The above graph shows the indifferent point between good and bad lot and the
average outgoing quality is 0.023165.
P Pac AOQ
0.01 0.8601 0.008601
0.05 0.4633 0.023165
0.1 0.2059 0.02059
0.15 0.0874 0.01311
0.2 0.0352 0.00704
0.25 0.0134 0.00335
0.3 0.0047 0.00141
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14. How should Sue Wilson develop a total quality management (TQM) program
given the conditions which exist in the case? Describe some specific actions she
could take to improve quality at DecFab.
Sue Wilson can develop a TQM program by considering the following factors: -
Top management
commitment and
involvement
Customer involvement
Design products for
Quality
Design production
process for quality
Control production
process for quality
Developing supplier
partnerships
Building teams of
empowered employees
Benchmarking and
continuous
improvement
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Top management commitment and involvement : -
As it is seen from the case that when Mr. Hanson manufacturing V.P. formed a
problem solving team to solve the problem of dental drill production process there
is a strong resistance from the department heads for the same. Also when Sue
Wilson tried to establish a stronger commitment to quality there is a great deal of
resistance among the managers, including John Baldridge. So there is no support or
involment of the top management for anything good implemented in the
organization. Hence, there must be stronger commitement from the top
management.
Customer involvement : -
It means the company must identify the customer’s wants and then incorporate the
wants into product design. So, it is nothing but giving customers what thay want.Thus, DecFab can use this tactic.
Design products for Quality : -
It means excellence in the performance, features, reliability, durability, appearance
and service are affected by the product design. So the product design must be of
quality one and that which is based on what the customers need. So, DecFab must
accordingly design its products.
Design production process for quality :
Machinery and workers play an important part of the production process so it must
be designed to produce the products with dimensions of quality that the customers
want. So, DecFab must redesign its production process.
Control production process for quality : -
It means DecFab must exercise continuous monitoring and control on the production process to ensure that only products of superior quality are produced.
Developing supplier partnerships : -
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It means DecFab must select and develop suppliers that fits into the TQM system.
DecFab must try to develop long term relationships with the suppliers so that they
deliver parts of perfect quality which the customers want.
Building teams of empowered employees : -
It means the company must train, organize, motivate and empower its employees
to produce and extend the availability of products and services of perfect quality.
Benchmarking and continuous improvement : -
It means DecFab must set certain standards or benchmark of comparison withrespect to its competitors to measure the progress and performance on a continuous
basis as well as take corrective actions whenever possible.
Specific actions that Sue Wilson can take to improve the quality at
DecFab :
o Sue Wilson can make use of Quality function deployment tool for
identifying customer wants and eliminating wasteful product features and activities
that do not contribute to product quality. Through this tool she can identify the
product features that need improvement.
o Sue can form Quality Circle (QC) i.e. a formation of group of employees
who will meet on a regular basis to undertake work related projects designed to
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improve working conditions, self-development and to advance the company by
using the quality control concepts.
o Sue Wilson can make use of certain Statistical process control tools like
Pareto diagram and process flow diagram to identify the most important problems,
find out the percentage of defectives in the process, eliminate them and improve
the efficiency of the production process.
o Sue can make use of various control charts like Run charts to find out
whether the production process is within the control or not and take corrective
actions as soon as possible.
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15. Describe a course of action for the Problem-Solving Team, in addition to that
mentioned in the case.
The problem solving team can take the following actions : -
There is a lack of communication between departments regarding marketing,
designing and production of any product, so the communication gap must be filled
up first by arranging some training programs or programs that aims to improve
communication skills.
They can conduct Quality Audit by appointing a quality control inspector
who can do the inspection of the entire unit or control the production process.
Proper training programs can be arranged for the employees and workers
regarding how to work efficiently.
They can arrange seminars or workshops for creating or encouraging more
and more interests in work for workers and employees.
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They can organize visits to some good companies plant for analyzing how
they operate, how they carry out all activities efficiently, how there production
process is, how they maintain their quality levels etc.
They can set certain standards or benchmark for the production process and
do continuous comparison of the actual performance with the standards set to find
out the deviations or defects.
The major problem here lies with the poor machining issue which is internal
problem, so regular repairs and maintenance or checking up of all machines i.e.
whether they are working at their fullest capacity or not is necessary.
The second important problem is bad incoming parts. Here DecFab adopted
bidding system in the past for giving contract to vendors but they must give
contract to them on the basis o f the information they have gathered about that
vendor, his reputation in market, quality of his parts etc and not just on the basis of
lowest cost of the bid.
So, we think that if these above two problems are solved as soon as possible then
DecFab can definitely become a well known brand in the market among the
customers as it was in the past.