Process control at PolaroidChulanunt Thaiyanunt

Basing your analysis on both quantitative and qualitative tools, what evidence is there

that quality is getting better?

Pod Weight control

According to Pod Weight control chart in Appendix, the pod weight performance variability is within the

control limit (between 2.774 - 2.835), which means the process is in control. This indicates the quality is

getting better since the Pod Weight defect rate is normal (Pod Weight measurement is a part of defect

report issued by operator, which continue 1% after Greenlight implementation) and in control, although

they reduce the number of quality control samples. However, each average of sample of the last five

shifts has decreasing trend. Therefore, Polaroid might want to investigate the cause before the process

is out of control.

Less Quality Control expense

Since quality control activities do not add value to the Polaroid camera, a company normally wants to

reduce the cost of quality control as much as possible. In Polaroid, the quality control process itself can

increase the defect rate and makes the sampling product to be reworked. Therefore, reducing the

number of samples by implementing Greenlight saves the company’s expense.

Standardize the process

Prior to the Greenlight project, the process quality at Polaroid was rely on operators’ individual

performance since each of them had their own mindset how to handle the machines from their

experience. The knowledge of dealing with machines belonged to operators, not the company. The

Greenlight project s provides the standard direction, which benefits to the company since now the

knowledge belongs to the company.

Basing your analysis on both quantitative and qualitative tools, what evidence is there

that quality is getting worse?

Finger Height control

The control chart of Finger Height measurement in appendix is not as good as Pod Weight. 20 of 45

sampling data are out of control. Moreover, the interval between the maximum and average value and

the minimum and average value is almost equal in each shift unlike Pod Weight control chart. This

means the process at Polaroid is already stable since variant is almost the same but the operators still

tweak the machines if they feel it would improve the process quality. Finally, the trends of control chart

are different when compared by each shift. Most of data in shift A exceeds the upper control limit while

data in shift B is mostly in control and below the lower control limit in shift C. The relation between

trend and operator shift further emphasize that the operators make adjustment to equipment on their

own.

Defect Rate reported by auditor

The defect rate reported by auditor is increased dramatically from around 1% to 10% after

implementing project Greenllight. The most type of defect detected is excess reagents (22%, according

to Exhibit 5), which is not fatal since customers would never aware of this type of defect but they still

consider it as a defect. The increase of excess reagents from 10% to 22% causes Polaroid wasting their

money than before because they have to rework more defects that do not affect the customer’s

satisfaction.

What recommendations would be in order to (further) improve quality?

Investigate the cause of problem

Most of samples of Finger Height measurement are out of control. Polaroid should investigate the cause

of this problem so they can prevent the same problem occurred in the future. Also, the expense of

process control quality will be reduced after finding the cause.

Ensure the operators follow the process

The company cannot precisely measure the quality of process if they do not have the data that reflects

the actual process. In order to collect the meaningful data, Polaroid has to ensure everyone follow the

process, not adjust equipment on their own.

Revise the types of defect

Some types of defect, such as excess reagents, are not related to customer’s need. The quality controls

of these measurements cause unnecessary expense for the company. If the company can reduce the

number of controlled defect types, they will save the expense while maintain the product quality.

Appendix

Pod Weight Control Chart

Form base-line data in exhibit 3, mean and standard deviation can be calculated as 2.805 and 0.025,

respectively.

Polaroid set control limit at 3 standard deviations

UpperControl Limit=μ+3 ρ /√numberOfSample

¿2.805+3(0.025)/√6

¿2.835

LowerControl Limit=μ−3 ρ /√numberOfSample

¿2.805−3(0.025)/√6

¿2.774

By using mean, maximum and minimum value of Pod Weight sample in each shift, the control chart of

Pod Weight can be draw as the following diagram

2.720

2.740

2.760

2.780

2.800

2.820

2.840

2.860

2.880

Mean UCL LCL Max Min

Finger Height Control Chart

Form base-line data in exhibit 3, mean and standard deviation can be calculated as 2.805 and 0.025,

respectively.

Polaroid set control limit at 3 standard deviations

UpperControl Limit=μ+3 ρ /√numberO fSample

¿2.805+3(0.025)/√6

¿2.835

LowerControl Limit=μ−3 ρ /√numberOfSample

¿2.805−3(0.025)/√6

¿2.774

By using mean, maximum and minimum value of Finger Height sample in each shift, the control chart of

Finger Height can be draw as the following diagram

1.600

1.700

1.800

1.900

2.000

2.100

2.200

2.300

2.400

2.500

2.600

Mean UCL LCL Max Min

Finger Height Control Chart of Shift A

1.500

1.700

1.900

2.100

2.300

2.500

2.700

Mean UCL LCL Min Max

Finger Height Control Chart of Shift B

1.700

1.800

1.900

2.000

2.100

2.200

2.300

2.400

Mean UCL LCL Min Max

Finger Height Control Chart of Shift C

1.500

1.600

1.700

1.800

1.900

2.000

2.100

2.200

2.300

2.400

Mean UCL LCL Min Max