This "Process Control at Polaroid (A)" case study discusses the initial move of a film production plant to shift to a worker-based process control from a traditional QC inspection.
Steven C. Wheelwright; H. Kent Bowen; Brian Elliott
Harvard Business Review (693047-PDF-ENG)
November 05, 1992
Case questions answered:
- What is the magnitude of the cost of quality problems at the R2 plant? How effective were its past procedures for quality management?
- Using the data in the exhibits and the note on process control charts, construct and analyze the appropriate SPC charts. What conclusions should Rolfs draw?
- What recommendations would you make to Rolfs in order to address both near- and longer-term issues?
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Case answers for Process Control at Polaroid (A)
This case solution includes an Excel file with calculations.
Summary of the Process Control at Polaroid (A) case study
The quality control processes at the R2 assembly plant of Polaroid were inefficient and traditionally based on destructive sampling. Sampling destroyed a perfectly good product and created scrap. With Project Greenlight, Statistical Process Control was brought in. However, the defects detected by the quality auditors rose to 10x, while defects reported in production processes fell to half. $540k was the cost of sampled scrap in QC alone in 1984. Operator sampled scrap was $740k, and defective returns were $2 million. Global word-wide revenues were $1.3 billion.
For Bud Rolfs, the manager heading the SPC, the perception of SPC is an area of concern. The external customer complaint information will take another eight months to be able to conclusively comment on the effect of quality. At the same time, he has to instill confidence in the management that his project didn’t sacrifice quality. Also, he has to convince the staff that quality comes from controlled and capable processes and not from ‘tweaking’ the machines.
He also has to make a decision to be able to send Microline (current measurements tool) data to the computer directly. Or to purchase more complex data capturing device, which will cost $100k more, and require a full-time operator.
What is the magnitude of the cost of quality problems at the R2 plant? How effective were its past procedures for quality management?
Detailed Description of the quality problem
Teams responsible for Quality control at Polaroid
Traditionally, at Polaroid, two groups were responsible for the quality of the instant films being manufactured at plant R2.
- Production Operators who were responsible for the overall production process
- The quality control department (QC) had the final responsibility for release to the market of all films. They used to check the final product for defects. This group was called QC auditors.
Roles and Responsibilities of the two groups –
- Production operators: At each stage of the process, they sampled 32 cartridges (3 or 4 times per hour) out of a lot of 5000, and took measurements of different parameters of product to check quality. They rejected about 1% of the production. They didn’t frequently record the data.
- QC auditors: They sampled 20 finished cartridges, on an average, from a lot of 5000 cartridges to see for defects. They rejected 50 cartridges from the lot, which was just over 1% of the product
Problems with current Quality checking process
Production operators rejected the lot based on the operator knowledge of the equipment, they would determine to reject the entire lot, or a portion of it, or just one product. There is no control limit to determine the rejection criteria.
The production operators didn’t make any measurements on the random sampling.
Each maintenance person had their own set of solutions to fix the abnormality of the machines. Maintenance was an “art”. Operators used to ‘tweak’ machines based on their own experience to deliver quality.
There was a tendency to keep machine utilization at the highest, and therefore the operators allowed defects to actually happen before shutting down the lines.
There was some initial success to demonstrate the principles of SPC at Polaroid. In 1981, mechanical engineers and maintenance personnel would use to bring each machine back to ‘target specifications’, rather than fixing it in the shortest time (so line utilization isn’t affected). The baselining effect was that the yield rose up. However, traditional process control measures and analyses continued to be done by process engineering technicians without the support of other departments like engineering, maintenance, and quality control.
If the production operators were uncertain of the quality, they would send off to QC auditors, with the belief that QC auditors will be able to catch defects and make a decision to reject the lot.
The 125 member team of QC inspectors were…