3 MANAGEMENT
Design management involves the following activities:
• Setting the objectives
• Planning
• Communicating the plans
• Monitoring and controlling the execution of the plans
• Reviewing the outcome.
BS 7000, Guide to Managing Product Design, uses these basic activities to structure the Guide which is based upon the product development model shown in Figure 4. The Guide is split into three main sections, each addressed at a different level of management: senior management, project managers and design managers. At the end of each main section of the Guide there is a useful checklist of key points.
IDEA (MARKET NEED)
DESIGN
MANUFACTURING INSTRUCTIONS
PRODUCTION
PRODUCT OPERATION
SCRAP
ACTIVITIES RESULTS
Figure 4: The BS7000 product development cycle
4 FUNCTIONAL TO PHYSICAL TRANSFORMATION
The central activity of engineering design is the conversion of a set of technical requirements into a set of manufacturing instructions. Central to this activity is the transformation from a functional description of the proposed product or system to a physical description, see Figure
5. At the beginning of any project, the proposed product is described in terms of a set of functions which it must fulfil. A mountain bike must, for example, transport the rider over rough terrain as comfortably and safely as possible. To achieve this a number of technical functions must be achieved including: provide power transmission, vary gear ratio, provide suspension,
provide braking, provide steering, ensure adequate strength, ensure easy maintenance, etc. All these must be achieved in such a way that the resulting bike is economical to manufacture and is robust enough to provide a reasonable life, bearing in mind its intended use. The list of functions could be greatly extended, but the key feature is that no mention has been made about how these functions are to be fulfilled - they are essentially solution-neutral. Solutions must be found for all the required functions and these solutions transformed into physical descriptions of what is to be made. Completing this transformations is an extremely complex information processing activity.
TECHNICAL J
REQUIREMENTS
/
INFORMATION PROCESSING ACTIVITY
FUNCTIONAL 1 PHYSICAL
DESCRIPTION J DESCRIPTION
TRANSFORMATION
" ./
MANUFACTURING INSTUCTIONS
Figure 5: Functional to physical transformation
All technical systems can be modelled in terms of the flows and conversions of material, energy, and information (signals). This "function" model must be mapped onto the structure of a technical system as shown in Figure 6.
INPUTS OUTPUTS
MATERIAL MATERIAL
ENERGY
INFORMATION
FLOWS
&
CONVERSIONS
ENERGY
INFOR.,M..ATION
BOUNDARY OF TECHNICAL SYSTEM
Shape - Maceria/ - Manufaccure
Figure 6: Structure of a technical system (product)
All technical systems exhibit the same hierarchical structure. The mountain bike represents a technical system (product) which uses physical effects to handle material, energy and signal flows. The system can be broken down into a number of assemblies, for example frame, handle bars, pedals, brakes, gears, etc. Each assembly can be broken down into individual parts, such as wheel rim, spoke, spindle, etc. For each of these parts, the shape will have to be defined, the appropriate material selected and the optimum method of manufacture chosen. Some parts are purchased as standard components from specialist suppliers, for example ball bearings, roller chain, Bowden cables, etc. All specially manufactured parts and bought-in components must be assembled together using the appropriate joining and fastening techniques to build assemblies, which are in turn connected together to build up the final product.
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