| Last time we discovered that clearly written instructions are one of the desired end results of the Development stage of the systems engineering approach to medical device design. We learned that one of the objectives of these instructions is to make sure the devices are manufactured in a cost effective manner and with minimal defects during the Production stage.
Other instructions created during the Development stage are those addressing quality control inspections and testing instructions. The objective of the quality control department is to ensure that, during the Production stage, the end product has been assembled correctly, making use of the prescribed parts, and absent manufacturing defects. This end is achieved by virtue of the fact that the quality control department staff is usually not under the management of the engineering or manufacturing departments, therefore they are positioned to offer an impartial assessment of the production process. An undesirable side effect of quality control’s impartiality is that because they are not intimately involved in the design process, a great deal of collaboration must take place between them and design engineers to produce quality control instructions which meet objectives. To this end, many discussions must take place concerning subject matters as diverse as requirements for component dimensions, component material properties, and the proper assembly of parts. Next time we’ll continue our discussion on the Development stage by further examining how instructions are developed to ensure that the quality control department meets its objectives while performing inspections and tests during the Production stage. ___________________________________________
|
Posts Tagged ‘testing’
Systems Engineering In Medical Device Design – Instructions, Part 2
Monday, January 14th, 2013
Systems Engineering In Medical Device Design – Concept Evaluation
Monday, December 17th, 2012| How many times have you bought something and lugged it home, only to discover that it didn’t work as advertised? These days this scenario is all too common. Chances are it was developed haphazardly and rushed into production without adequate research and testing. A chief contributor to the product’s not living up to expectations is very often the result of a poor beginning. In its concept and development stages, design engineers failed to use a systems engineering approach.
Last time our discussion of the Concept stage of systems engineering identified stakeholder requirements as being of three basic types, serving the needs of functionality, performance, and constraint. Once identified, these requirements were incorporated into a detailed specification that is approved by all stakeholders involved, then used to devise alternate medical device concepts in order to really size things up. Let’s now move on to the Development stage of the design process to see how the alternate concepts are evaluated. The Development stage of the systems engineering approach to medical design begins with research and development of alternate device concepts. Stakeholder requirements as defined in the original product specification are used to guide the process, then mockups and prototypes of the alternate concepts are built, tested, and analyzed in view of the requirements. Considerations such as cost, ease of manufacture, operation, durability, and potential risk of harm to users are evaluated. As often happens, the best alternate concept satisfies all but a few of the specified requirements, resulting in a “good enough” scenario. That is to say, if stakeholders can agree the requirements not met aren’t all that important in the scheme of things, they may be willing to remove them from the specification, thus approving the concept for further development. If an agreement such as this cannot be reached, it may be necessary to return to the Concept stage and begin the entire process again. This re-evaluation of the process should result in a set of requirements that are further refined and from which better options in alternative concepts can be developed. Next time we’ll continue our discussion of the Development stage and see what it takes to finalize design and begin manufacture. ____________________________________________
|
