Synopsis - Disposable Medical Device Quality and Productivity Analysis

Disposable Medical Device Quality and Productivity Analysis

Contents:
	Executive Summary
	Findings
	Background Information

Executive Summary

A confidentiality agreement will not allow use of the names of the disposable medical device or the company. However, the findings presented in this summary should be sufficient to highlight the analysis of quality and productivity issues. This summary and its findings are based on a review of company documents, direct examination of the production process, and interviews with quality, supervisory, and production personnel.

Overall disposable set quality is extremely high. The problems that do exist have been identified are being worked. The most significant of these is the use of design specifications as control limits for the manufacture of a critical component, instead of statistical limits. In part, this choice represents a key source of the undesirable variability in these plastic parts.

The implementation of Just-In-Time (JIT) production to improve productivity is blocked by the part variability problem.

Findings
Finding #1:	*Upper and lower control limits of X-Bar and Range charts for the critical part were incorrectly determined.*
Impact:	This situation generated delays in detecting out-of-control conditions within the process. Additionally, a perceived in-control process may actually be out-of-control, thereby creating a greater amount of variability in the manufactured part.
Analysis:	Examination of control charts revealed that design specifications were used for the upper and lower control limits, instead of statistically generated control limits. Such use of specification limits is a manifestation of the fallacy that conformance to technical specifications adequately defines quality.
Recommendations:	Examine all control charts for upper and lower control limits that use design specifications. Replace these with statistically generated control limits. Incorporate boundary limits into all statistical process control charts. This would permit faster and easier detection of out-of-control conditions.
Finding #2:	*Out-of-Control conditions are not detected in a timely manner and are not attributed to assignable causes.*
Impact:	This situation leads to the failure to detect significant variability in manufactured parts. The result may be ill-fitting parts on the assembly line and increases in the scrap rate.
Analysis:	Examination of control charts revealed that the Range chart exhibited an out-of-control condition (eight or more consecutive data points falling on one side of the average). In addition, the data on the Range chart suggests a cyclical pattern, possibly due to machine warm-up and cool-down characteristics or a change of operator. The X-Bar chart also revealed an out-of-control condition. All data points are located on one side of the average value. In all cases, personnel were not able to determine the assignable causes to the out-of-control conditions.
Recommendations:	Provide additional training in the proper construction of control charts and out-of-control process detection. These efforts, coupled with the inclusion of boundary limits on the control chart, should be speed the detection and correction of out-of-control conditions.
Finding #3:	*The disposables general quality procedure, and the Monthly Quality Audit do not include reviews of statistical process control charts.*
Impact:	Improper control construction and use may go undetected. Excessive variation, with resulting delays and increased scrap rates, may go undetected.
Analysis:	A thorough examination of existing procedures and Monthly Quality Audit documentation revealed very comprehensive guidelines encompassing document review, sample testing and destructive inspection. However, there were no audit procedures in place for determining if the processes for individual components were in control.
Recommendations:	Develop inspection criteria for auditing control charts and criteria for re-evaluating the variance of control limits. Coordination with engineering may be required to institute the necessary reduction in variance. Conduct this additional inspection in conjunction with existing quality audits. Train personnel as required.

Background Information

Company

The company under study is a leading worldwide medical specialties company that designs, develops, manufactures and markets products for use in cardiovascular surgery, blood salvage, critical care monitoring, blood component technology and hemodialysis. The company's research, development and manufacturing operations are focused on providing products and services for the handling, treating, monitoring and processing of blood outside the body, as well as for the collecting of specific blood components used in the treatment of diseases. The company operates under the FDA's Good Manufacturing Practice (GMP) regulatory requirements.

Product

The product and process selected for analysis is the manufacture of a disposable set. The application of the disposable set involves the collecting, cleaning, and returning of the patient's blood during surgery. This technology reduces the need for donor blood transfusion, thus reducing the risk of exposing the patient to contaminated blood (e.g., HIV+).

The disposable set is used in conjunction with a machine unit. The machine pumps the blood, separates out the impurities (via centrifuge), filters the blood and returns it to the patient.

P.O. Box 374 Littleton, Colorado 80160-0374
303.798.6092 sdtaylor@taylorqualitygroup.com