PLANNING AND DESIGN
ENGINEERING DESIGN
PRINCIPLES OF DESIGN
PHILOSOPHY OF DESIGN
1)
2)
3)
4)
5)
6)
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
METAL PRODUCTS ENTERPRISE
FIRST LEVEL STRUCTURE
METAL
PRODUCTS
ENTERP RISE
LEGAL
SERVICES
MATERIAL
SUPPLIES &
PROCUREMENT
SALES &
MARKE TI NG
PRO DUCTION
OPERATIONS
PRODUCT
ENGINEE RING
FINANCE &
ACCO UNT ING
HUMAN
RESOURCES
Analysis and Optimization
• 2
METAL PRODUCTS ENTERPRISE
SECOND LEVEL STRUCTURE
METAL
PRODUCTS
ENTERPRI SE
LEGAL
SERVICES
MATERIAL
SUPPLIES
&
PROCUREMENT
SALES &
MARKETING
PRODUC TIO N
OPERATIO NS
PRODUCT
ENGINEERI NG
FINANCE &
ACCOUNTING
RAW
MATERIAL
STO RES
PRODUC TIO N
SCHEDULING
MANUFAC TURING
PROC ESS
C ENTR ES
PRODUC TIO N
CONTROL
FINISHED
GOODS
STO RES
HUMAN
RESOURC ES
Analysis and Optimization
• 3
METAL PRODUCTS ENTERPRISE
THIRD LEVEL STRUCTURE
METAL
PRODUCTS
ENTERP RISE
LEGAL
SERVICES
MATERIAL
SUPPLIES
&
PROCUREMENT
SALES &
MARKE TI NG
PRO DUCTION
OPERATIONS
PRODUCT
ENGINEE RING
FINANCE &
ACCO UNT ING
RAW
MATE RIAL
STORES
PRO DUCTION
SCHEDULING
MANUFACTURING
PRO CESS
CENT RES
PRO DUCTION
CONT ROL
FINISHE D
GOODS STORES
RAW
MATERIAL
STORES
WELDI NG
SHOP
MACHI NE
SHOP
FOUNDRY
QUALI TY
CONTRO L
HUMAN
RESOURCES
Analysis and Optimization
• 4
METAL PRODUCTS ENTERPRISE
FOURTH LEVEL STRUCTURE FOR MANUFACTURING
METAL PRODUCTS
ENTERPRISE
LEGAL
SERVICES
MATERIAL
SUPPLIES &
PROCUREMENT
SALES &
MARKETING
PRODUC TION
OPERATIO NS
PRODUCT
ENGINEERI NG
FINANCE
FINANC E&&
ACCOUNTING
ACCOUNTING
RAW MATERIAL
STO RES
PRODUC TION
SCHEDULING
MANUFAC TURING
PROC ESS C ENTRES
PRODUC TION
CONTROL
FINISHED
GOODS STO RES
RAW MATERIAL
STO RES
W ELDING
SHOP
MACHINE
SHOP
FOUNDRY
QUALITY
CONTROL
MACHINES
MACHINES
MACHINES
MACHINES
MACHINES
MATERIALS
MATERIALS
MATERIALS
MATERIALS
MATERIALS
OPERATIONS
SCHEDUL ES
OPERATIONS
SCHEDUL ES
OPERATIONS
SCHEDUL ES
OPERATIONS
SCHEDUL ES
OPERATIONS
SCHEDUL ES
MEN/WOMEN
(SKILLS)
MEN/WOMEN
(SKILLS)
MEN/WOMEN
(SKILLS)
MEN/WOMEN
(SKILLS)
MEN/WOMEN
(SKILLS)
HUMAN
RESOURC ES
Analysis and Optimization
•
TABLE 4: MACHINE[1] TYPES AND SIZES IN THE RAILWAY
MACHINE SHOP
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
•
•
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
Part/Hour
No of cut
Setting time
Feed
Rev/min
Width
Speed
Length
Diameter
Machine
Oper No
Shop
Stage No
2
4
1
2
3
4
Item No
2
Date
1
Quantity
3
Number
2
Order
Date
3
Route card: Return to planning
1
Description
1
Tooling
Material for one
TABLE 6: PROCESS SCHEDULE FOR CENTRE PIVOT-ITEM NO. 14/549
Operation
PROCESS SHEDULES FOR
PART IN MACHINE SHOP
•
•
•
•
PROCESS PLAN FOR CAST STEEL CENTRE PIVOT (STAGE 4ELABORATION)
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
1)
2)
3)
4)
5)
•
•
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);
1)
2)
3)
4)
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.