FICCI CE Reliability improvement techniques FICCI CE

FICCI CE Reliability improvement techniques

FICCI CE Reliability has been defined as quality over time. It is the ability of the product to satisfactorily perform its designated function over its customer intended life time.

FICCI CE Product Reliability Quality improvement has two faces - internal and external. Internal quality improvements deals with reduction of scrap, rework, inspection costs etc. External quality improvement means enhancing the performance that the customers experience throughout the product’s life span.

FICCI CE Product Reliability The major gains of external quality come from reduced field repairs, recalls, warranty, product redesign etc.

FICCI CE Product Reliability Another benefit is the increase in future sales not only for the product in hand, but for the additional product the company manufactures. For example the improvement in the reliability of motorbikes can also favorably impact the company’s sale of cars.

FICCI CE Techniques of improving product Reliability is the part of quality that affects the customers the most. To achieve reliability improvement it is essential that management insists on comprehensive reliability improvement program at the product design stage itself.

FICCI CE 1. Reliability should be proactive

FICCI CE Reliability should be proactive As per Henry Ford if you need an equipment to improve the product reliability but don’t buy it, you pay for it even though you don’t have it. The most important goal of product life data analysis is proactive reliability improvement preferably before the product release and at the DESIGN stage itself.

FICCI CE 2. Conducting Failure analysis To improve reliability one must understand why the failure occurred. Once the process has been established and the machinery has been acquired and set up, it is extremely important to determine the failure modes and effects they have on the customer.

FICCI CE Conducting Failure Analysis. . . A comprehensive and carefully designed product failure database is fundamental to trouble-free products. This database is the vital source of information to product developers about failures in similar previous designs. But, many other groups in your company also have needs for the data, often with slightly different requirements. These groups include: field service, customer service, warranty, accounting, procurement and inventory control, suppliers, and manufacturing.

FICCI CE Conducting Failure Analysis. . . For the design engineers, the data base should include for each failure: · Part that failed · Failure mode · Root cause of failure · Period in the life of the product of the failure (infant, useful, end) · Severity to customer · Statistical summaries of the data above

FICCI CE Conducting Failure Analysis. . . Engineers need to know in what period of life the part failed. Failures during the infant period may indicate a manufacturing defect rather than a reliability issue. Random failures during the useful life usually have other root causes, often correctable by better design. Failures at end of life may indicate wear and merit attention if they occur before the planned lifetime has passed. So, the failure database must collect and maintain data to indicate when the failure occurred.

FICCI CE Conducting Failure Analysis. . . Specialists often perform Failure Analysis because the field service people have a mission to satisfy the customer, not to analyze why the failure occurred. Failure Analysis strives to get to the root cause of the failure. Failure Analysis Reports should be well designed and integrated with the failure database. Design engineers should have a close working relationship with technicians performing failure analysis.

FICCI CE Conducting Failure Analysis. . . Knowledge about field failures is more valuable than knowledge from lab tests. Why? · The field failures occurred under true conditions in the hands of the customers. · The number of products being "tested" by customers is very large, giving more statistically valid results.

FICCI CE 3. HALT Highly accelerated life testing (HALT) is becoming popular among reliability and design engineers for faster elimination of key failure modes before product release. The objective of HALT application is to rapidly identify failures, which may require long time to discover under normal use conditions. Such testing is typically done on a few prototype units that are subjected to combinations of stresses at much higher levels than encountered in a normal operation.

FICCI CE 4. Robust design experiments 1. Robust design experiments have great potential for leading to improvements in products and process design, and thus, reliability. The key idea behind robust design methods proposed by Taguchi is to choose design conditions that make the product robust to environmental factors. Car crash tests are examples of testing robust designs in real conditions.

FICCI Product Design - Checklist ( For improving reliability ) CE

FICCI CE Product Design Controls Product design controls can be categorized in 3 parts I. Means of knowing the product II. Means of testing designs III. Means of regulating designs

FICCI CE I. Means of knowing the product ã Do the designers know the variety of application of the product. ã Do they have complete information on the operating environments. ã Do they have access to the user to discuss applications. ã Do they know the potential field misuses of the product.

FICCI CE Means of knowing the product. . . l l l l Do they have clear understanding of product requirement on : Performance Life Warranty period Reliability Maintainability Accessibility Safety Operating costs

FICCI Means of knowing the product. . . ã Have the non quantitative features of the product been defined in some manner? ã Do the designers know the level of product sophistication suitable for the user involved? ã Are adequate design guidelines, standards, handbooks and catalogues available? ã Do the designers understand the interaction of their part of design with remainder of the design? CE

FICCI CE Means of knowing the product. . . ã Do the designers understand the consequences of a failure or other inadequacies of their designs on: 1. The functioning of the total system 2. Warranty costs and 3. User costs ? ã Do they know the relative importance of various components & characteristics within components? ã Do the designers know what are the manufacturing capabilities relative to the design of tolerances?

FICCI Means of knowing the product. . . ã Do the designers derive tolerances based on customer/functional needs or just use standard tolerances? ã Do the designers know the shop and field costs incurred because of incomplete design specifications or designs required in change? CE

FICCI CE II. Means of testing designs ã Do the designers have the means of testing their design with regard to the following : ã a. Performance & reliability tests ã b. Tests for unknown design interaction or effects ã c. Pilot run ã Is their an independent review of design? ã Have the detailed drawings been checked?

FICCI CE Means of testing designs. . . ã Do the designers record analysis for the design? ã Do the designers receive adequate feedback from development tests, manufacturing tests, acceptance tests and user experience? ã Are the results quantified where possible including frequency of problems and costs to the manufacturer and user?

FICCI CE Means of testing designs. . . ã Does failure information contain sufficient technical details on causes? ã Are the designers aware of material substitutions or process changes? ã Do the designers receive notice when their designs specifications are not followed in practice?

FICCI CE III. Means of regulating Design ã Have the designers been provided with the means of regulating the design process? ã Are they provided with information on new alternative materials or design approaches? ã Have they been given performance information on previous designs? ã Are the results of research efforts on new products transmitted to the designers?

FICCI CE Means of regulating Design. . . ã Are the approvals required from the designers to use products from the new suppliers? ã Do the designers participate in defining the criteria for shipment of the product? ã Can the designers propose changes involving trade-offs between functional performance, reliability and maintainability?

FICCI CE Means of regulating Design. . . ã Are designers told of changes to their designs before they are released? ã Have causes of design failures been determined by thorough analysis? ã Do designers have the authority to follow their designs through the prototype stage and make design changes where needed? ã Can the designers initiate design changes?

FICCI Means of regulating Design. . . ã Are field reports reviewed with designers before making decisions on design changes? ã Do designers understand the procedures and chain of command for changing a design? CE