27 01 16s

Pagina 1

1 Solution Exercise 1 ITEM A A suggested disassembly precedence graph ITEM B Profit maximization. Calculate Delta value and highlight the components economically unsustainable. Data of the problem: • C = {c1,c2,…,cnC}: the set of all parts and components. • R: precedence matrix. • RCi: The revenue which is gained from re-using target component or subassembly I, • DCi: The cost of recycling or disposing un-reusable non-target component or subassembly I, • BCi: The marginal cost of disassembling a target subassembly or component. • Ti: Task time, • FC: Fixed cost per operation time unit. • STCi,j: Set-up cost of removing component/subassembly j after component/subassembly i. Decision Variables: • CT = {0,1,0,….1}: Binary vector representing if component ci is disassembled (target component). • Seqi: Sequence of disassembly of target components/subassembly. Objective function: Strategy to solve question: If there are no set -up times/costs, then the sequence is not affecting the objective function. Therefore, the problem reduces to calculate the optimal disassembly level. Solution options: Extensive search. Repeat for 2C times the following steps. 2 • Generate vector CT. • Compute R. Select the solution with higher value of R. However, if we have 16 components, then 65536 solutions exist (they might be unfeasible for the precedence graph). Parts list Task time (tu) EoL Value (euro) Revenue/comp Delta Hazardous 1 PCB 12 15 3 Yes 2 Fingerprint scanner 2,5 2 -0,5 No 3 GPS module 3 7 4 Yes 4 Numerical keypad 1 0 -1 No 5 Functional keypad 1 0 -1 No 6 Camera-video module 2 4 2 No 7 Camera-photo module 2 5 3 No 8 LCD 5 8 3 No 9 Display cover 1 0 -1 No 10 Rechargeable battery 2 5 3 Yes 11 Upper frame 0,5 0 -0,5 No 12 Lower frame 0,5 0 -0,5 No 13 Flip mechanism 0,5 1 0,5 No 14…