ENGINEERING DESIGN PRINCIPLES OF DESIGN PLANNING AND DESIGN ENGINEERING DESIGN PRINCIPLES OF DESIGN

PHILOSOPHY OF DESIGN Recognition of need; Definition of problem; Formulation, synthesis, or creation, of a concept or possible solution; Analysis and optimisation (of the concept); Presentation; Evaluation.

Definition of problem Manufacture of Metal Products Metal Part

Concept: Metal Products Enterprise

Analysis and Optimization 2

Analysis and Optimization 3

Analysis and Optimization 4

Analysis and Optimization TABLE 4: MACHINE[1] TYPES AND SIZES IN THE RAILWAY MACHINE SHOP CENTRE LATHE HEXAGONAL TURRET LATHE FOR BAR WORK DRILLING MACHINES MILLING MACHINES SHAPERS SLOTTERS: GRINDING MACHINES SEATS PLANNERS SHEARING MACHINES: BORING MACHINES OTHER MACHINES 388150 ton Press 1955 200 Ton Wilkins Press 3861 150 ton Wilkins Press1954 30 ton Press1923 H.B Matic 3945 Band Saw 46E. Tapping Buffing machine. [1] Detailed list in Appendix A

LAYOUT OF MACHINE SHOP Layout of Machines in Railway Machine Shop

CENTRE PIVOT SPECIFICATION

PROCESS SCHEDULE

PROCESS SHEDULES FOR PART IN MACHINE SHOP PROCESS PLAN FOR CAST STEEL CENTRE PIVOT (STAGE 4-ELABORATION) Lastly, a processing plan, often referred to as process schedule (route card), is designed for each part or product that is to be processed in the manufacturing facility. Process schedules are a feature of batch production of metal parts and products. It is a record of the optimal timetable of processing operations, methods, and stages for the production of a metal part. The process schedule is information recorded on paper, outlining material to be used, machines and tools to be used, operations to be performed, instructions to be followed, dimensions and tolerances to be achieved To produce the metal part. It is an investment in knowledge, which is re-used as many times as the part is produced in the manufacturing facility.

PROCESS SHEDULES FOR PART IN MACHINE SHOP Slide 11 shows the process schedule for manufacturing the cast steel centre pivot in the machine shop of the Kenya Railways workshops. The process schedule is the software version of the technology of production. It is, similar to technological hardware such as dies and moulds, from which repeated batches of metal parts may be produced. In jobbing or one-off production, a process schedule may not be justifiable because repeat orders are not expected. It is for the same reason that dies and moulds may not be justified for one-off production. In the case of mass production, all products are processed through the same process schedule, which is therefore a permanent list of activities. An example is the water treatment works where raw water is passed through a permanent sequence of inoculation, sedimentation, filtration and disinfection process.

PROCESS SHEDULES FOR PART IN MACHINE SHOP The final plan (process schedule) for the manufacturing facility analyses part shown in Drg. No. 2, to determine processing timetable shown in Table 6, through the organisation in Figure 4, the machines listed in Table 4, and facility layout Drg. No. 1, In terms of types and quantities of: Output of parts quantities: (Sales/production programme); Materials: Machines: Men/Women: Input manpower skills Methods: Machine operations required to convert inputs into outputs

PROCESS SHEDULES FOR PART IN MACHINE SHOP Process schedules are then the most detailed plans for producing a single metal part. The process schedule is an activity plan, and is simply a list and timetable of activities required to produce the metal part. The philosophy of design is also a plan for the design activity, in the same way that the process schedule is a plan for the activity of producing a metal part. The stages of the design activity designated philosophy of design, are artificially shown as discrete, but, being part of a process, they actually merge into each other, and have no rigid boundaries.

PRESENTATION (STAGE 5): This is the stage of communicating the results of the design or planning exercise. The stage of presentation is therefore vital in establishing the existence of the plan or design. This existence of a plan is established by communicating the content of the plan through available communication media, such as reports, drawings, and oral presentation.

PRESENTATION (STAGE 5): A physical plan consists of a list of parts and their layout. Such a layout may be a map showing the developments of housing and infrastructure in an urban area, the layout of machines in a machine shop (DRG. NO. 1), the assembly of parts into a machine, or the drawing of a single part (DRG. NO. 2). On the other hand, an activity plan consists of a list of activities and their timetable. The process schedule shown in Table 6 is an example of an activity plan.

PRESENTATION (STAGE 5): The presentation of a design or a plan will therefore contain the list of parts and their layout for a physical plan, or the list of activities and their timetable for an activity plan. These therefore comprise the content of the written and graphic (drawings) reports. Each activity stage in the philosophy of design requires the application of logic appropriate to the stage and field of design or planning. Such logic is only verifiable if the decisions at each stage are recorded graphically or in a report, and are therefore available for scrutiny and retrospection.

PRESENTATION (STAGE 5): Every plan or design starts as a possible solution (concept) in the mind of an individual. This idea or concept is thereafter developed and converted from an initially intangible form, into a material record of logical decisions. This record of logical decisions is what is eventually refined into lists of parts, activities, layouts, timetables, and presented in the form of reports, drawings, and oral presentation.

PRESENTATION (STAGE 5): The presentation of a plan or design through reports and drawings is the final stage of transforming intangible thought into tangible plans. A plan or a design therefore exists only when it can be presented in available modes of communication. It may be possible for an individual to crystallise an idea in his mind well enough so that he/she is able to implement it without passing through the presentation stage. This is how craftsmen sometimes work on simple parts. However, even in such cases, the prototype then becomes the plan or design for subsequent copies, and not the intangible idea in the craftsman's mind.

EVALUATION (STAGE 6) At the stage of evaluation, the design or planning results obtained and presented are compared with the objectives or performance requirements specified at the target setting stage of definition of the problem. Evaluation starts with the assessment of technical feasibility of the design, but ends with assessment of economic feasibility of the investment.

IMPLEMENTATION Implementation is not part of the design or planning exercise. Examples quoted for the planning or design of an industrial enterprise, illustrate the application of the philosophy of design to elaborate a solution to a design or planning problem. After the plan of the enterprise is completed, it can then be implemented by providing the prescribed population of physical structures, machines, men, materials and services, and process schedules. Thereafter, production from the enterprise can commence when management places orders for the delivery of a specified quantity of goods or services.