<title>Changes In Manufacturing, Testing and Process Control</title>

Abstract

AbstractDuring the last few years manufacturing test engineers have been exposed to a new setof terminologies that include lasers, laser safety, isolated test areas, clean rooms,precision fixtures, assembly procedures, and alignment procedures. In addition to thechanges in terminologies, both research and development engineers and manufacturing testengineers have found themselves responsible for test procedures and assembly procedures dueto the requirement of alignment and alignment checks during and after assembly of electro-optical systems and subsystems.Due to the changes in engineering responsibility, management has made several smallbut general changes to ensure an earlier interface during the research and developmentphase between the manufacturing and research and development organizations. Becausethis early interface has been missing with some of the earlier electro- optical systems,the process control efforts in manufacturing have not kept pace with the research anddevelopment areas.Examples of areas in process control in which there are great and immediate needs foradvancement include bonding of optical components, optical coatings, and mechanical mounts.It is the intent of the author to present both problems and solutions encountered duringpast projects and to point out anticipated problems on future systems and how this newknowledge is being used to head off future problems.IntroductionThe introduction of electro- optics into tactical weapon systems has brought aboutnumerous changes in all areas of engineering development and manufacturing. Both thecustomer and the defense contractor are finding it necessary to reevaluate their capa-bilities in management, manpower, and facilities to ensure producibility, maintainability,and testability of electro- optical (EO) systems and subsystems. One area most profoundlyaffected, however, is that of manufacturing testing and process control, where not onlymanufacturing test engineers, but research and development engineers have now found them-selves responsible for test and assembly procedures due to the requirement for alignment andalignment checks during and after assembly of electro- optical systems.The requirement for optical alignment has effected changes in many areas of responsi-bility. Both the changes and the areas affected are shown in Tables I and II along thepoints of interaction. As can be seen from Table II, manufacturing test has been impactedmore from changes caused by optical alignment requirements than any other area of responsi-bility. This paper will discuss these changes from two aspects: first by discussingchanges due to optical alignment requirements in the different areas of responsibility byusing the changes in manufacturing to illustrate the effects; and second, by discussingthe changes and their interaction.Changes and Effects on ManufacturingManagement first became aware of the impact of optical alignment requirements when facedwith requests for large expenditures for capital equipment to establish EO test facilitiesensuring proper alignment of assemblies. The increase in the number and accuracy of opticaltests required to perform and verify alignment drove up production costs so drasticallythat trade -offs had to be implemented to determine alternate methods of system design thatcould accommodate and maintain alignment requirements without the performance of extensivein- process optical assembly tests. In turn, these significant cost and scheduling changeshave forced design to unit production cost (DTUPC) considerations to be initiated at a muchearlier point in the system development phase.In response to management's request for earlier attention to DTUPC, research and develop-ment engineers were forced to give optics a greater degree of attention during system de-velopment phases. Project managers, who formerly had mainly a mechanical or electronicsbackground, now found they needed an optics background to perform well in positions ofauthority in the design and fabrication of systems. Mechanical components had to be design-ed and fabricated to match the optical components in size, shape and tolerances. At the