3. PROCESS PLANNING DEFINITION:
• Set of instructions describes mfg product and its parts.
• Operations planning as systematic determination of engg processes
and systems to mfg a product competitively and economically.
• Prepare work instructions for mfg and assembly of components to
product in discrete mfg environments.
• Systematic determination of methods products to be
mfg,economically and competitively.
• Consists of selection of mfg processes and operations,production
equipment,tooling and jigs and fixtures,
4. • Determination of mfg parameters,specify selection criteria for quality
assurance ensure product quality.
IMPORTANCE OF PROCESS PLANNING:
• Link between engg design and shop floor mfg,product is how
mfg,production costs and profitability,indepth of knowledge,
equipment capabilities, tooling availability, material processing
characteristics, shop practices.
PRODUCT DESIGN AND MFG CYCLE:
• Intermediate stage b/w designing the product and mfg.
• Three main functions marketing and sales,design,mfg.
6. PROCESS PLANNING: LINK B/W DESIGN AND MFG:
• Cross functional teams are employed to design and mfg
functions,known as simultaneous or concurrent engg.
8. RESPOSIBILITIES OF PROCESS PLANNING ENGINEER:
• Part print analysis and symbols.
• Fundamentals of product design(rough stock, production
• Machining processes(setup time,quality,type and cost of tooling).
• Operations sequence,inspect the equipment,production
tolerances,cutting tools and cutting conditions,overall time by work
14. PROCESS PLANNING ACTIVITIES:
• Analyse finished part in engineering design.component
finish,material specification,part required).
Material evaluation and process selection:
tivity,cost).Evaluate the materials, (features,dimensions,geometric
tolerances transform rough state to finished state).Process
evolution(rough to finished).Part evolution(final state to initial state).
15. Selection of m/c,tooling,workholding devices:
• Economic considerations,production rate per unit cost,durability and
dependability,lower process rejection,minimum setup times,long life
of m/c,functional versatility.best m/c,make or buy,BEA .
Selecting process parameters:
• Machines selected,calculating operation setup time and cycle
time,tooling sequence,equipment capability,shop practice.
• Calculation of part processing time requires determination of
sequence of processing steps on each m/c as outplanning.
• Part loading,unloading,m/c indexing for 1 cycle.
• M/c cycle time allowances added to standard cycle time.Calculate
cycle time & m/c rates to find out cost.
16. Selecting quality assurance methods:
• Inspection criterias(dimensional,geometric,surface finish),tools and
• Process of determining the probable cost of product before
• Material,labour,overhead costs-profit.
• Material,mfg processes,batch size,make or buy.
17. Process planning documentation:
• Document clearly all the detail information.
• Documented as job routing or operating sheet.
• Production operations&associated m/c tools for component and
• Route sheet information as
part identification,processing,operation of m/c,std times,setup cycle
times,tooling requirements,production control information shows
planning lead time operation.
• Reasons: part process-design,job quote,cost estimate,std cost
18. Communicate process knowledge:
• Mfg to shop floor,economy,consistent quality.
Inputs and outputs of process planning:
• Route sheet and operation sheet as single sheet.
19. PROCESS PLANNING METHODS(APPROACHES TO PROCESS
• Manual process planning(traditional,workbook approaches).
• Computer aided process planning(retrieval,generative).
Manual process planning:
• Process plan prepared manually.
• Examine and interpret eg,m/c process,equipment selection,opns
sequence,shop practices,skill,judgement and experience,different
• Product opns,manual tools(feed,speed,setup time,opns
time),documented as routing sheet.
20. Workbook approach:
• Modified version uses developed workbook prepares route sheet.opns
sequence of products the drawing interpretation is carried by
Uses of manual approach:
• Small scale companies,flexible,low investments.
Drawbacks of manual approach:
• Complex,time&data high,skill process,human error,skill,judgement
and experience,increases paper work,productivity down,no response
to mfg environment,process,tool,materials…
Computer aided process planning:
• Computers reduces clerical works,rational,consistent and optimal
plans,interface between cad and cam.
21. Benefits of capp:
• Process rationalization and standardization,productivity
improvement,product cost reduction,eliminate human error,time
reduction,reduces clerical and paper work,legibility improves,fast
response to engg changes,incorporation of application programs.
Retrieval or variant capp systems:
• Widely used in machining applications,similar parts have similar
plans,new part recalls,identifies,retrieves existing plan for similar
modified new parts.
Benefits of retrieval capp systems:
• Standard plan,variety of parts,simple programming and
installation,understandable,easy to learn and use.
Drawbacks of retrieval capp systems:
• Planned components limited to previous planned.
• Experiences modify standard plan.
22. Generative capp systems:
• Computers synthesize individual process plan automatically w ith or
without reference to prior plan.
• Decision logics and precoded algorithms,mfg using
equipment,specific process plan for specific part.
• Inputting GT code as part design,monitoring the functions.
• Part description,subsystem define m/c parameters&select and
sequence individual operations,database,report generators.
Advantages of generative capp:
• Consistent process plan,new components,integrating automated mfg
facility provides detailed control information.
Drawbacks of generative capp:
• Complex and very difficult
25. SELECTION OF PROCESS PLANNING SYSTEM:
• Numerous engg management decisions,identify,weight and compare
• Best process plan-general environment,organisational
structure,technical expertise,needs and objectives of MIS.
30. DRAWING INTERPRETATION:
• Prepares process plan for product,functional requirements of
design,assembled with dimensions and tolerances.
• Information such as material,designation,coding,no of
parts,weight,dimension of parts,geometric tolerances,size and
• Engineering drawing:Language of engg and
communication,orthographic projection(accurate mfg
design,2D&3D,pictorial gives more information).
Types of drawing:
• Detail drawings:single-part,collective.
• Assembly drawings:single-part,collective.
• Combined drawing.
• Provide all the information required for mfg of
product,(dimensions,tolerances,surface finish and material
31. Types: single part,collective single part.
Single part drawings:
• Complete detail information single component mfg without reference
sources.shape,dimension,tolerances,size and locations,heat
Collective single part drawings:
• One or two dimensions of component are variable,others being
• Machines and mechanisms consist of numerous parts and a drawing
shows complete product with all components in correct physical
• Drawing gives small part of whole assembly.
• Single part,collective
32. Single part assembly drawings:
• Information to build single sub-assembly or assembly.
• Part list,quantity,overall dimensions,weight,mtrl specifications,design
data,operational details and instructions.
Collective assembly drawings:
• Range of products similar in appearances,differ in size,mfg and
Combined detail and assembly drawings:
• Assembly with part list and details of these parts on one
drawing,small one-off reduces scheduling and printing.
INFORMATION ON THE DRAWING SHEET REQUIRED FOR
PROCESS PLANNING:(CRITICAL PROCESSING FACTORS):
• Dimensions: complete dimensions of the component design mfg.
• Functional: Influence operated part.
• Non-functional: Not influence operated part.
• Auxiliary: Not relate to operate and mfg part.
33. Material specifications:
• Parts evaluated,specified and manufactured.
Special material treatments:
• Material properties treated.
Tolerances,limits and fits:
• Component fit assembly,appropriate lower and upper limits.
• Accurate tolerance,cost high,good engg practice.
• 10±0.02 as 9.98&10.02mm.
• Unspecified tolerances dimensions,saves time.
Limits and fits for shafts and holes:
• Basic size is shaft or hole size,limits the specified design.
• Basic hole system-basic hole size adjusts shaft size to fit.
• Basic shaft system-basic shaft size adjusts hole size to fit.
34. • Standard tools as drills,reamers for basic hole system.
• Tightness or looseness for application of tolerances to mating parts.
• Assemble/dissemble by hand,running and sliding assemblies,low cost
to high temperature,minimum accuracy.
• Press tooling,close accuracy,no interference.
• Forced permanent assemblies,retain and locate.
• Permissible variation of form,attitude.
35. Surface finish:
• Irregularities depth of surface in mfg processes.
• Longer wavelength deviations of surface to nominal surface,large
scale problems,errors in m/c tool ways,guides,inaccurate alignment of
• Finest irregularities of surface,production process.
• Widely space deviations from norminal shape,m/c vibration.
• Surface texture=roughness+waviness.
• Surface roughness,surface textures(symbols), Surface
roughness,surface textures(components) used.
41. Material selection and evaluation:
• Component-material processing-mfg-design.
Metals and classification:
• Materials of iron as prime constituent,steel(0.05-2%),iron(2-4.5%).
• Alloys of iron and carbon,carbon steels and alloy steels.
• Low carbon steel 0.25%C,Medium carbon steel 0.60%C,
High carbon steel-0.60%C.
• Alloy steels-chromium,nickel,molybdenum,vanadium,tungsten,cobalt.
• Low alloy steels-3 to 4%,high alloy steels-5%(alloying elements).
• Important alloy steels-stainless steels,tool steels,HSLA
• Ferrous alloys of iron 2 to 4.5%C,3.5% silicon.
42. • Grey cast iron-low cost,white cast iron-hard and brittle,malleable cast
iron-ductile,yield and tensile strength,spheroidal graphite cast iron.
• Elements other than iron as chief constituent.
• Light weight,colour,ease fabrication, better resistant, electrical and
• Important non-ferrous materials-C,Al,lead,Ni,Mg,Ti,Tn,Zn.
• Density, thermal and electrical insulation, resist to
• Features-(melting temp,oxidation,corrosion,high temp).
• Composed of two or more different materials, resultant materials
superior to individual materials.
• Particle reinforced composites-Particles of one material dispersed in a
matrix of second material.
• Fibre reinforced composites-Dispersed phase as fibre.
45. MATERIAL SELECTION PROCESS:
• Appropriate material for product under consideration is complex task.
• Translation-design requirements as constraints,objectives,free
• Screening-constrained limits apply to subset of viable materials.
• Ranking-ordering material,excellence criteria,maximum or minimum.
• Supporting information-
MATERIAL SELECTION METHODS:
• Computer aided databases,performance indices,decision
matrices,expert selection,value analysis,failure analysis,cost-benefit
49. Process selection
• shaping, joining, finishing, mfg-design, size, shape and
• Material form, size and weight, economic considerations, dimensional
and geometry accuracy, surface finish,batch size, production rate.
• Prototype validate mfg,compare mfg to assembly costs for different
55. Process selection methods(steps):
Mfg process,difficult,complex and systematic
• Materials selected,specified.
• Design documents,information comprehensive.
• Starting point for process selection.
• Material,shape,size,tolerance,roughness,process parameters.
• Three analysis and o/p-geometry analysis,mfg information,material
evaluation and o/p.
Identification of critical processing factors:
• Combined o/p from drawing interpretation analysed and correlated.
Comparison of potential mfg processes:
56. • Correlate,appropriate,decision-making,economy data.
• (Labour,equipment,tooling cost,batch and production rates),costing
methods and comparisons.
Identification of suitable processes:
• Part-primary-secondary-critical processing.
Production equipment and tooling selection:
• Mfg-processes-production equipment.
Factors for equipment:
• Size,weight,physical size,construction,power and torque, no of tools,
type of tools.
Factors for tooling:
• Availability,w/p,type,part geometry,tool material,m/c data,m/c tool
characteristics,cutting tool materials,tool holding,quality,capability
60. Machine selection methods(steps):
First cut selection: Identify,specify,select mfg processes,physical
size,type of machine.
Power/force analysis: Specify.
Capability analysis: Dimensional,geometry accuracy,surface finish,m/c
Final selection: More than 1 machine.
62. Factors in tooling selection:
• Constraints on tool selection- Mfg practice,mfg process,m/c tool
characteristics,capability,processing time, cutting tool availability.
• Operating requirements on tool selection-W/p material,operation,part
geometry, tooling data.
• Tooling performance affecting factors-Cutting tool materials, cutting
tool geometry, cutting fluids.
Constraints on tool selection- Mfg practice,mfg process,m/c tool
characteristics,capability,processing time, cutting tool availability.
• Tool actually fed to workpiece.
• Two categories(continuous cutting,intermittent cutting).
• Continuous cutting-cutting tool is continuously fed to w/p.
• Intermittent cutting-cutting tool not continuously fed to w/p.
• M/c tools limit the selection of tooling.
63. M/c tool characteristics:
Work holding devices,Tool structure,Power o/p,
Feed and speed of m/c.
• Dimensional and geometric accuracy,surface finish.
Cutting tool availability:
• Selecting the available tools.
Tool selection operating requirements-W/p materials,operation,part
• Heat generation,cutting tool geometry material.
• Specific cutting tool.
64. Part geometry:
• Specific geometry feature.
• Mfg tooling data,suitable tools,specified operations.
Tooling performance factors- cutting tool materials,cutting tool
Cutting tool materials:
• Tool performance,hss,carbides,cast non-ferrous alloys,ceramics.
Cutting tool geometry:
• Tool angles,rake angles,cutting edge angles,tool nose radius.
• Influences w/p material and tool material.
Cutting fluids usage:
• Cools w/p,tool temperature,maintains hardness,avoid distortion.
• Friction b/w tool and w/p,wear resistance of tool,improves tool