Cost effective production of metal injection moulded parts: R.C. Drewes, (Advanced Forming Technologies Inc, Longmont, Colorado, USA)

Abstract

Customers of high-technology industrial process control instrumentation systems are demanding that these systems provide enhanced functionality, features, and flexibility. Examples are: an integrated system with a distributed architecture, user-friendly configuration and reconfiguration control and monitoring from an operator's console, supervisory and optimizing contiol through the use of Computer Interfacing, trend and other historical recording, built-in diagnostics and error message handling, and other Management Information Systems capabilities.Customers are also demanding that these systems give improved performance, including reliability, maintainability, and availability (RMA). To ensure that these RMA performance characteristics are met during the design, development, manufacture, and deployment (use) of the equipment requires Reliability, Quality Control, and Quality Assurance Programs be put in place. The Design and Development Program must include redundancy and back-up operating modes for any critical functions, methods of operating around any single, critical hardware failure (this may include software methods) and, in cases of critical control loops, the back-up operating modes also need to include continuous automatic control even for the unusual case of the operator losing all communication to the control process instrumentation. This also would need to allow repair by replacement of the local primary Controllers while operating online in a back-up mode. These capabilities plus built-in diagnostics will improve maintainability, reduce downtimes, and thereby improve availability.Improving reliability will then reduce required maintenance actions, which will also improve availability. The entire Reliability Program is aimed at assuring and improving reliability. The Reliability Program includes the following major parts:Component QualificationsIC Screening to the Equivalent of MIL-STD-883 Quality Level B-2Component Design Derating RequirementsDesign Reviews, including Stress and Application AnalysesHardware and Software Reliability Growth TestingThe Reliability Growth Testing consists of:Board Level TestingSubsystem TestingSoftware Integration TestingSystem Functional and Hardware TestingThis paper describes the Reliability Growth Testing that has taken place for the Taylor™ MOD 300™ System product line, the advantages that are being experienced from that testing for that 3rd-generation microprocessor-based control instrumentation equipment, and also some of the improvement results. In the manufacturing area the expected results of getting further Reliability Growth (reducing infant mortality failures from getting into the field) by applying an all-equipment Environmental Stress Screening (consisting of a powered and monitored temperature cycling test) is also described.