Process Planning and Cost Estimation

Process Planning and Cost Estimation

1. PROCESS PLANNING AND COST ESTIMATION D.PALANI KUMAR, Assistant Prof. / Mech. Engg., Kamaraj College of Engg. & Tech. Virudhunagar

2. Unit 1

3. process planning Activities involved to convert design into the product.

4. Types of process planning Manual process planning Traditional approach Workbook approach Computer aided process planning Retrieval process planning (variant) Generative process planning

5. Traditional approach Manual Based on process planner experience and intuition it will vary. Stages Stage 1  process planner interpret product drawing Stage 2  refer manual Stage 3  documenting routing sheet

6. Workbook approach Modified version of the traditional approach Referring workbook Workbook  which contains predetermined sequence of operation (standard procedures).

7. Advantages of manual process planning Suitable for small scale industries. Highly flexible . Low investment costs.

8. Disadvantages of Manual process planning Time consuming process. Need a skilled process planner . Possibilities for human error . Inconsistent process plan.

9. Computer aided process planning ( CAPP ) why we need to go for CAPP? Overcome the drawbacks of Manual process planning. Reduce the routine work of manufacturing engineer. Act as an interface between CAD and CAM.

10. Benefits of CAPP (2 mark) Productivity improvement. Production cost reduction Elimination of human error . Product standardization .

11. Approaches of CAPP Retrieval CAPP system (variant approach) Generative CAPP system

12. Retrieval CAPP system Concept  similar parts will have similar process plan . Process plan for a new product is created by recalling, identifying or retrieving the existing plan for similar product .

13. Retrieval CAPP system (procedure)

14. Advantages of retrieval CAPP Once a standard plan is produced, similar plans can be produced using existing plan . Simple programming (when compared to Generative type). Easy to learn and use . Commercially available retrieval CAPP systems are  MultiCapp and MIPLAN

15. Generative Process plan In generative approach, the process plan were generate process plan automatically without any reference to prior plan . Concept  the concept is based on decision logics and pre-coded algorithms .

16. Components of Generative process plan Part d escri p ti o n Sub system (define mac h i n i n g p arameters) Subsystem (define sequence of operation ) database Report g enerat o r

17. Advantages of generative CAPP Generate consistent process plan. New components can planned easily Integrating with an automated manufacturing facility. Example  APPAS,CMPP,EXCAP,XPLAN

18. Drawing interpretation First step Getting information from the drawing. Prepared by design department. Details required Material of the component, its designation Number of parts to be produced Weight of the component Dimensions of the part Dimensional and geometric tolerances Size and accuracy of the parts

19. Engineering drawing Universal language Projection Orthographic Pictorial Types of drawing Detailed drawing Assembly drawing Combined drawing

20. Detailed drawing Detailed drawing  Single part drawing Collective single part drawing

21. Single part detailed drawing

22. Collective part detailed drawing

23. Assembly drawing Assembly drawing  Single part assembly drawing Collective assembly drawing

24. Single part assembly drawing

25. Collective assembly drawing

26. Combined drawing

27. Information on the drawing sheet required Geometric and dimensions ( complete dimensions ) Material specifications ( material code , example  SS310 ) Notes of special material treatments ( like heat treatment ) Dim e nsion a l t o l e r an c es ( uppe r limit a n d l o w er limit e g: 10±0.2 ) Geometric tolerances ( straightness, flatness, roundness ) Surface finish specifications ( roughness and waviness ) Tool references Gauge references Quantity to be produced Part lists

28. Material Evaluation Second activity of process planning. Material selection (done by design engineer) Choose the material Material evaluation (done by process planning engineer) Check the chosen material for further process

29. Material properties

30. Classification of materials

31. Metals and their classification

32. M e t als Based on iron content Ferrous(iron more) Non ferrous (iron content less)

33. F er r ous Ferrous Steels (carbon percentage less than 2%) Cast iron (carbon percentage more than 2%)

34. S t eels Steels low alloy steel (percentage of alloying element is less than 5 %) Low carbon steel (mild steel) (carbon percentage less than 0.25%) Medium carbon steel (0.25 % to 0.6 % ) High carbon steel (more than 0.6 %) High alloy steel (percentage of alloying element is more than 5 %) Tool steel Stainless steel (chromium content is more than 12 %)

35. Cast Iron Cast iron (carbon percentage more than 2 %) Grey  most widely used White  hard and brittle Malleable  highly malleability Spheroidal Graphite cast iron (SG cast iron)  high ductility.

36. Non ferrous materials Non Ferrous materials (iron content low) Example  Aluminium, Copper, Lead, Tin, Zinc, Nickel, Titanium, Magnesium Properties Light in Weight. High electrical and thermal conductivity. Better resistance to corrosion. Ease of fabrication. Colour.

37. P olymer Polymers  a substance which has a molecular structure built up chiefly or completely from a large number of similar units bonded together .

38. Polymers Classification

39. Ce r amics Ceramics  A ceramic is any of the various hard, brittle, heat-resistant and corrosion- resistant materials made by shaping and then firing a nonmetallic mineral , such as clay, at a high temperature.

40. Ceramics Properties Ceramics are strong, hard and brittle . Can be used at high temperature . They are good thermal and electrical insulators .

41. Ceramic Example Alumina Silicon Carbide Silicon nitride Sialons

42. c omp o si t es Composites  composites are the combination of two or more materials having superior properties than the original materials.

43. Composites Classification

44. Material selection process (procedure)

45. Material evaluation method Steps Shape and geometry considerations Dimension Size Surface finish Material property requirements Mechanical Physical service Manufacturing considerations Interchangeability Quality assurance Ease of manufacturing and assembly

46. Steps in process selection Process  method of shaping, joining and finishing We need to choose right process.

47. Manufacturing Process

48. Classification of process

49. Factors in process selection Material form Component shape and size Economic consideration Dimensional and geometric accuracy Surface finish Batch size Production rate

50. Steps in Process Selection Drawing interpretation ( process-shape matrix ) Identification of critical processing factors ( process material matrix ) Comparison of potential manufacturing process ( compare ) Identification of suitable process ( select )

51. Process shape matrix

52. Process material matrix

53. Production equipment and tooling selection Selection of production equipment (machine) Selection of tooling (tool)

54. Factors consider Production equipment selection (machine) Technical factors Physical size Machine accuracy Surface finish Cutting force Operational factors Batch size Capability availability

55. Tooling selection constraints

56. Stages in tooling selection Evaluation of Process and tooling selection Analysis of machining operations Analysis of workpiece characteristics Tooling analysis Selection of tooling

57. UNIT 2

58. Process Planning Activities

59. Process Planning Activities Process parameter calculation for various production process Selection of jigs and fixtures Selection of quality assurance methods Set of documents for process planning Economics of process planning Case studies

60. Process Parameter calculation for various production process Process Parameter Cutting Speed Feed and Feed rate Depth of Cut

61. Cutting Speed Cutting Speed  Relative speed between tool and workpiece Unit  mpm

62. Cutting Speed Factors affecting cutting speed Nature of cut work material Cutting tool material Cutting fluid application Purpose of machining Kind of machining operation Capacity of machining tool Condition of the machine tool

63. Cutting speed

64. Cutting speed

65. Cutting speed (formula)

66. Turning problem Turning a rod of 60 mm diameter and the maximum spindle speed is 500 rpm. calculate the cutting speed in m/min.

67. Cutting speed (formula)

68. Shaping problem

69. Feed and Feed Rate Feed  distance through which the tool advances into the workpiece Feed rate  rate at which cutting tool advances the workpiece . Unit  mm/rev or mm/min

70. Factors affecting feed rate

71. Feed rate for turning and boring

72. Feed rate for drilling

73. Feed rate for milling

74. Depth of Cut Depth of cut  thickness of material removed in one cut. Depth of cut is always perpendicular to feed direction Unit  mm

75. Speed, feed, and depth of cut h t t p s : //w w w . y out u be. c om/ w a t ch?v=N N 3vOblJQ Q8

76. Selection of Jigs and Fixture Work holding device  to position and hold the work piece in precise location while manufacturing operation. General work holding devices Vices Chuck clamp Special work holding devices Jigs fixtures

77. Jigs and Fixture Jigs Which locate and hold the workpiece and guides the tool Fixture Which locate and hold the workpiece and does not guide the tool.

78. Jigs and Fixture animation https://www.youtube.com/watch?v=5m5HqE y_Jqs

79. Functions of jigs and fixtures C hris Strikes L ong R aining S ixes Clamping  exert force to press the workpiece Supporting  supporting machines Locating  position the workpiece Resist forces Safety factors

80. Reason for using jigs Reduce the effort of setting workpiece Reduce production cycle time Semi skilled labour employed Reduce the cost of inspection

81. Factors considering during selection of jigs and fixture Physical characteristics of tool and workpiece Type and capacity of machine Study of safety and ejecting devices Required level of accuracy

82. Types of jigs and Fixtures Types of Jigs Drill Jig  drilling, tapping, chamfering, spot facing, reaming countersinking Boring Jig Types of Fixture Turining, milling, grinding, broaching, boring, taping, welding, assembly

83. Selection of quality assurance methods Quality is fitness for use ( Juran ) Quality assurance  maintenance of a desired level of quality Selection of quality assurance methods for critical factors Critical factors Dimensional tolerance Geometry tolerances Surface finish

84. Steps involved in quality assurance Identification of inspection location Identification of most appropriate inspection technique Determination of frequency of testing Evaluation of inspection and test data Identification of corrective data

85. Quality Quality Assurance Strategy Detection Strategy Prevention Strategy

86. Detection Strategy

87. Prevention Strategy

88. Statistical tools of Quality

89. Statistical tools of Quality

90. Statistical Quality Control

91. Statistical Quality Control

92. Statistical Quality Control Descriptive Statistics  mean, median, mode Statistical process control  using control charts Acceptance sampling  samples are taken to decide quality

93. Control chart Attribute Vs Variables

94. Inspection and measurement Maintain the product quality Stages Pre-production inspection Inspection during production Post production inspection

95. Inspection and measurement Types 100% inspection Sample inspection

96. Inspection and measurement Inspection of attributes (surface finish, accuracy) Inspection of variables (with quantitative numbers)

97. Measurement Instruments

98. Inspection of attributes

99. Inspection of variables

100. Inspection of variables

101. Factors to be considered while Selecting measuring instruments Accuracy Linearity Magnification Repeatability Resolution Sensitivity stability

102. Set of documents required for process planning

103. Set of documents required for process planning

104. Set of documents required for process planning

105. Economics of Process planning Process planner should have fundamental knowledge on cost estimating, cost accounting, various types of costs, components of cost and calculation of cost of the product manufacturing

106. Economics of Process planning Knowledge of costing will help process planner and management for taking following decisions Type of material to be used Type of manufacturing process Volume of product Make or buy decision Design of a product

107. Break even analysis It is graph plotted between sales and volume

108. Break even analysis Break even analysis  it is a study of inter relationships between sales, cost and operating profit at various levels of output . Break even point  no profit no loss (revenue=cost)

109. Break even analysis To help in deciding profitable level of output To compute cost and revenue for all volumes To take decision regarding make or buy To take plant expansion decisions

110. Break even Point Algebraic method Graphical method

111. Algebraic method

112. Graphical method

113. Case Study

114. Process planning activities Step 1  Analyse (Drawing interpretation) Spindle have to be manufactured 60 mm dia and 130mm length Spindle consist of three concentric cylinder One internal thread and one external thread have to be cut

115. Process planning activities material of the component is mild steel Dimensional tolerance is 0.05 Number of parts to be made = 200

116. Process planning activities Step 2  Identification of operation involved and sequence of operation First operation  turning from 60 mm diameter to 50 mm diameter for 130 mm length

117. Process planning activities Second operation  50 to 40 for 110 length Third operation  40 to 35 for 65 length Fourth operation  drilling 10 mm dia for 45 mm length Fifth operation  internal threading Sixth operation  external threading

118. Process planning activities

119. Process planning activities

120. UNIT 3 INTRODUCTION TO COST ESTIMATION

121. Syllabus

122. Topics to be covered Cost Estimation (Estimation) Vs Cost Accounting (Costing) Importance of Cost Estimation Types of estimates Elements of cost estimation Estimating procedure

123. Topics to be covered Importance of Costing Methods of costing Elements of Costing Estimate of labor cost and material cost Allocation of overhead charges Calculation of depreciation cost

124. Cost Estimating (Estimation) Process of determining the probable cost of the product before the start of manufacture.

125. Cost Accounting (Costing) Process of determining the Actual cost of the product after the manufacturing.

126. Importance of cost estimation Important for all organizations . Important for deciding manufacturing and selling policies . Problem Overestimating  problem with competitive prices Underestimating  will lead to financial loss

127. Objective of cost estimation To establish selling price of product To verify the quotation by vendors To take make or buy decision To prepare production budget

128. Types of estimate Preliminary cost estimate Final Cost estimate

129. P r elim i na r y c o s t e s tim a t e Based on incomplete data Less Accurate Suitable for new project Procedure With drawings Without drawings

130. Final Cost estimate Based on complete data Most Accurate Huge amount of money spent to make the estimate

131. Classification of cost estimates based on design level Conceptual phase (cost estimate accuracy ±30%) Preliminary design phase (cost estimate accuracy ±20%) Detailed design phase (cost estimate accuracy ±10%)

132. Methods of Estimate Conference method Comparison method Detailed analysis method

133. Methods of Estimate Parametric Estimating Uses relationship between the historical data and other variables Statistical Estimating Sampling or random sampling used in general study for variable

134. Data Requirements for cost estimating

135. Data Sources for cost estimating

136. Data Sources for cost estimating

137. Data Sources for cost estimating

138. Possible Estimation Over Estimation Under Estimation Realistic Estimation

139. Elements of cost estimation

140. Design Cost

141. Drafting Cost

142. Cost of Research and Development

143. Materials Cost

144. Labour Cost

145. Inspection Cost

146. Maintenance Charges

147. Overhead Cost

148. Cost Estimating procedure

149. Cost Estimating procedure

150. Cost Estimating procedure

151. Cost Estimating procedure

152. Cost Estimation Form

153. Cost Accounting (Costing) Process of determining the Actual cost of the product after the manufacturing.

154. Importance of Cost Accounting Determining , classifying and analyzing the cost and income of business firm Determining prices to be quoted to customers Forming basis for managerial decision To make or buy decision To introduce new product or drop on existing one

155. Importance of Cost Accounting Cost control through the accumulation and utilization of cost data. Establishing standard for measuring efficiency.

156. Estimating Vs Costing

157. Methods of Costing Job costing Batch Costing Process costing Department costing Operating cost method Unit cost method Multiple cost method

158. Job costing Method is concerned with finding cost of the individual job Suitable for job order industries (ship building, machine manufacturing, fabrication, building contracts)

159. Batch costing Method concerned with instead of costing of separately, each batch of components is taken together. Used to determine the cost of group of similar products

160. Process Costing Method concerned with standard product with number of distinct processes performed in a definite sequence. Used in oil refining, chemical, paper making, paint , cement manufacturing

161. Department costing Method is suitable for cost of output of each department separately for the manufacture of standard products Used in Steel industry and automobile industry.

162. Operating cost method Method is suitable for company providing utility services Example  transport services, water works, electric board, Cost is based on operating expenses (per Km)

163. Operating cost method

164. Unit cost method Method is suitable for companies with the uniform product Example  mines, quarries etc.

165. Multiple cost method Method is suitable for companies producing variety of standardized products, with no relation between cost, quality and process.

166. Classification of cost

167. Elements of cost

168. Material cost Direct Material  material becomes the part of product Mild steel used for spindle Wood used for table Indirect Material  used to convert the direct material into finished product Greese, lubricating oil, coolant

169. Labour cost Direct Labour  labour directly work on the produt Welder, casting technician etc Indirect Labour  non productive staff to help the productive labour Supervisor, inspector, store keeper, watchman

170. Expen s es Direct Expenses  charged directly to the particular job Design manufacturing Indirect Expenses  other than material, labor and direct expenses.(Overhead charges)

171. Overhead charges Factory expenses Cost fuel, power and internal transport Repair and maintenance administrative expenses Charge of higher officials Office rent, legal charges, audit fees Selling expenses Cost of sales manager Cost of advertising Distribution expenses Packaging and delivery Store keeper unloading

172. Components of cost Prime cost Factory cost Production cost Total cost Selling Price

173. Ladder of Cost

174. Estimation of material cost Procedure

175. Estimation of material cost

176. Estimation of material cost

177. Estimation of Labor Cost Cost spent on workers who directly involve in the manufacturing operations. Formula Labor cost= standard time * cost of labour per hour Estimator should have knowledge on Operations involved Tools used Machines used

178. Estimation of Labor Cost

179. Estimation of Standard time problem

180. Estimation of Standard time (with allowances) problem

181. Estimation of Standard time (with allowances)

182. Calculation of Selling Price Problem

183. Calculation of Selling Price Problem

184. Allocation of Overhead

185. Depreciation

186. Causes of Depreciation

187. Methods of finding Depreciation fund

188. Straight line method Amount of depreciation distributed over the equal period of installments. Merit  simple method (little calculations) Demerit  this method does not consider maintenance and repair charges

189. Straight line method Formula

190. Straight line method Problem

191. Straight line method Problem

192. Straight line method Problem

193. Straight line method Problem

194. Diminishing balance method (Reducing balance method)

195. Reducing balance method Formula

196. Reducing balance method Problem

197. Reducing balance method Problem

198. Reducing balance method Problem

199. Sinking Fund Method

200. Sinking Fund Method Formula

201. Sinking Fund Method Problem

202. Annuity method In sinking fund interest amount earned invested on outside agencies but in this method invested within company.

203. Annuity method Formula

204. Annuity method Problem

205. Annuity method Problem

206. Sum of years digit method

207. Sum of years digit method Problem

208. Sum of years digit method Problem

209. Sum of years digit method Problem

210. Insurance Policy Method

211. Machine hour Method

212. Production Unit Method

213. Revaluation Method

214. Retirement Method

215. UNIT 4 PRODUCTION COST ESTIMATION

216. Syllabus

217. Topics to be covered Estimation of Forging Shop Estimation of welding Estimation of foundry shop

218. F o r ging Forging  Forging is a manufacturing process involving the shaping of metal using localized compressive forces.

219. Types of Forging Hot Forging Forging done above the Recrystallization temperature Cold Forging Forging done below the Recrystallization temperature

220. Forging process Hand forging Drop forging Press forging Machine forging

221. Forging operations Upsetting Drawing down Setting down Bending Punching Drifting swaging

222. Estimation of material losses in forging Shear loss Tonghold loss Scale loss Flash loss Sprue loss

223. Estimation of forging cost Material cost Labour cost Overhead cost

224. Forging Problem

225. Forging Problem

226. Forging Problem

227. Forging Problem

228. Forging Problem

229. Forging Problem

230. Forging Problem

231. Forging Problem

232. Forging Problem

233. Estimation in welding shop Welding  welding is the process of joining of similar or dissimilar metal by application of heat

234. Types of Welding Pressure Welding Non Pressure Welding

235. E s tim a tion o f w elding c o s t

236. E s tim a tion o f w elding c o s t

237. E s tim a tion o f w elding c o s t

238. E s tim a tion o f w elding c o s t

239. Estimation of foundry cost

240. Estimation of foundry cost

241. Estimation of foundry cost

242. Estimation of foundry cost

243. Estimation of foundry cost

244. UNIT 5 MACHINING TIME CALCULATION

245. Syllabus

246. Estimation of machining time Machining time is the time which machine works on the component. Eg: from the time tool touches the work to tool leaves the work

247. Terms used Length of Cut Cutting Speed Feed Depth of Cut

248. Length of Cut Approach Length Length of workpiece to be machined overtravel

249. Length of Cut

250. Cutting Speed Cutting Speed  Relative speed between tool and workpiece

251. Feed and Feed Rate Feed  distance through which the tool advances into the workpiece Unit  mm/rev o r m m /m i n

252. Depth of Cut Depth of cut  thickness of material removed in one cut. Depth of cut is always perpendicular to feed direction

253. Importance of machining time calculation Inorder to find out the machining cost Reduction of total manufacturing time , T Increase in MRR , i.e., productivity Reduction in machining cost without sacrificing product quality Increase in profit or profit rate, i.e., profitability.

254. Calculation of machining time for different lathe operation Turning Chamfering Facing Knurling Thread Cutting

255. Turning operation

256. External Relief Turning

257. Chamfering operation

258. Facing operation by lathe The process of reducing length of the material is called facing This can be done by the single point cutting tool

259. Facing (formula)

260. Facing operation

261. KNURLING KNURLING means creating cross linked pattern on the workpiece by lathe machine.

262. knurling

263. Machining time calculation for Drilling

264. Drilling Problem

265. Machining time calculation for Boring(formula)

266. Boring Problem

267. Mill i ng Milling is the removal of material from workpiece by rotary multipoint cutting tool. Operations Face milling Slot milling or slab milling Profile machining or forming Keyway cutting indexing

268. Milling operation

269. Machining time calculation for milling formula

270. Machining time calculation for milling

271. Determination of added table travel Face milling

272. Determination of added table travel Slot milling or slab milling

273. Machining time calculation for milling

274. Machining time calculation for milling

275. Machining time calculation for milling

276. Machining time calculation for Shaping

277. Machining time calculation for Shaping

278. Machining time calculation for Shaping

279. Machining time calculation for Shaping (problem)

280. Machining time calculation for planning

281. Machining time calculation for Grinding Grinding is the process of metal removal by abrasion. Methods of grinding Surface grinding Cylindrical grinding

282. Machining time calculation for Grinding (Formula)

283. Machining time calculation for Grinding (Formula)

284. Machining time calculation for Grinding (Problem)

285. Machining time calculation for Grinding (Problem)

286. Machining time calculation for Grinding (Problem)

287. THANK YOU