Design of assembly systems TS

Page 1

01. Assembly Systems = ∑ ∈ = ∑ ∈ 1 E XERCISE 1 You have a paced assembly line designed to produce according to a multi - model management. The data for each product are provided within the following tables. Product Model 1 Product Model 2 Operation Estimated time (min) Precedence Operation Estimated time (min) Precedence 1 2 - 1 3 - 2 4 - 2 2 - 3 4 - 3 2 1, 2 4 2 1, 2 4 2 3 5 6 3, 4 5 1 3, 4 6 4 3 6 1 3, 5 7 3 5 7 2 5 8 5 7 8 1 7 9 2 6, 7 9 2 6, 7 10 3 6, 8 10 2 8 11 3 9, 10 11 2 8, 9 12 1 11 Based on the expected production target , the two product models may work at the following cycle times: - 8 minutes / piece for product 1 - 6 minutes / piece for product 2 The maximum utilization rate to be adopted in order to design the line is  = 90 %. You are asked to: - d raw the precedence’s graph ; - d efine the minimum number of stations for each product ; - provid e an initial solution for assembly line balancing for each p roduct; - readjust the solution for assembly line balancing subject to the constraint to keep the same number of operators allocated to the line (1 operator for each station) ; - evaluate the Line efficiency , before and after the readjustment . P RECEDENCE ’ S GRA PH Product Model 1 Product Model 2 M INIMUM NUMBER OF STA TIONS 1.2.1 Product Model 1 - = 2 + 4 + 4 + 2 + 6 + 4 + 3 + 5 + 2 + 3 + 3 = 38 - Cycle Time = 8 min/piece α = 0.9 - [not considering the max value UR] - > = = ∑ ∈ = = 4 . 75  = = ∑ ∈ = . = 5 . 3 ≈ 1.2.2 Product Model 2 - = 3 + 2 + 2 + 2 + 1 + 1 + 2 + 1 + 2 + 2 + 2 + 1 = 21 - Cycle Time = 6 min/piece α = 0.9 - [not considering the max value UR] - > = = ∑ ∈ = = 3 . 5  = = ∑ ∈ = . = 3 . 9 ≈ I NITIAL SOLUTIO N = = ∑ ∈ = ∑ = 1.3.1 Product Model 1 = = 38 = = . . . . . . = = . = . % 1.3.2 Product Model 2 = = = = . . . . . = = . = % S…