An Application of Genetic Simulation Approach to Layout Problem in Robot Arm Assembly Factory Speaker ： Ho, Zih-Ping Advisor ： Perng, Chyuan Industrial Engineering and Enterprise Information, Tunghai University, Taiwan. IFORS at Hilton Hawaii Village, Honolulu, Hawaii. July 15, 2005.

Overview 1. Introduction 1. Introduction 2. Literature Review 2. Literature Review 3. Mathematical Formula 3. Mathematical Formula 4. GA Approach 4. GA Approach 5. Conclusion and Suggestion 5. Conclusion and Suggestion

Introduction (1)  The clean room space is expensive.  The robot arm equipment orders change over per three months.  It will move up and down in a semi-circle radius in 3D.  To make the maximum utilization of the clean room space.  The radius of robot arm movable areas is triple operations area than robot arm itself.

Introduction (2)  This research tries to apply a GA approach for dynamic layout problem.  When we finish a group of robot arm assemble, we will release the space of floor to the next robot arm.  It will compare the results of free spaces, occupied spaces, rotational spaces, due date and minimum processing time.

Literature Review (1) 1. Azadivar and Wang (2000) used GA to optimize facility layout problems. 1. Azadivar and Wang (2000) used GA to optimize facility layout problems. 2. Balakrishnan and Cheng (2000) proposed GA for dynamic layout problem. In their research, they used strings to represent one entire layout plan. 2. Balakrishnan and Cheng (2000) proposed GA for dynamic layout problem. In their research, they used strings to represent one entire layout plan. Azadivar,F and J.Wang (2000) Facility layout optimization using simulation and genetic Azadivar,F and J.Wang (2000) Facility layout optimization using simulation and genetic algorithms, Int.J.Prod.Res., 38(17): algorithms, Int.J.Prod.Res., 38(17): Balakrishnan,J. and C.H.Cheng (2000) Genetic search and the dynamic layout problem, Balakrishnan,J. and C.H.Cheng (2000) Genetic search and the dynamic layout problem, Computers and Operations Res., 27: Computers and Operations Res., 27:

Literature Review (2) 3.Balakrishnan et al. (2003) illustrated that the dynamic plant layout problem (DPLP) deals with the design of multi-period layout plans. 3.Balakrishnan et al. (2003) illustrated that the dynamic plant layout problem (DPLP) deals with the design of multi-period layout plans. 4.Li et al. (2003) used GA to solve the robust layout problem. 4.Li et al. (2003) used GA to solve the robust layout problem. Balakrishnan,J., C.H.Cheng, D.G.Conway and C.M.Lau (2003) A hybrid genetic Balakrishnan,J., C.H.Cheng, D.G.Conway and C.M.Lau (2003) A hybrid genetic algorithm for the dynamic plant layout problem, Int.J.Production Economics, 86:107- algorithm for the dynamic plant layout problem, Int.J.Production Economics, 86: Li,S.G., Z.M.Wu and X.H.Pang (2003) Machine robust facility layout problem in the dynamic and Li,S.G., Z.M.Wu and X.H.Pang (2003) Machine robust facility layout problem in the dynamic and flexible production environments, J. Shanghai Jiaotong, 37(5): ,769. flexible production environments, J. Shanghai Jiaotong, 37(5): ,769.

Literature Review (3) 5. Yang and Peters (1998) A robust machine layout design problem is an NP-complete problem, most researchers use heuristic approaches. 5. Yang and Peters (1998) A robust machine layout design problem is an NP-complete problem, most researchers use heuristic approaches. 6.Perng and Ho (2004) used database technique to help the company to solve the orders due date problem. 6.Perng and Ho (2004) used database technique to help the company to solve the orders due date problem. Yang,T. and B.A.Peters (1998) Flexible machine layout design for dynamic and uncertain production environments, European J. Operational Research, 108: Yang,T. and B.A.Peters (1998) Flexible machine layout design for dynamic and uncertain production environments, European J. Operational Research, 108: Perng,C. and Z.P.Ho (2004) Applying information technique to layout on semi-conductor equipments factory, The Third Conference on Innovation and Technology Management on Taiwan, Industrial Technology Research Institute on Taiwan, Xin-Zhu City, Taiwan, Sep.11, P.114. Perng,C. and Z.P.Ho (2004) Applying information technique to layout on semi-conductor equipments factory, The Third Conference on Innovation and Technology Management on Taiwan, Industrial Technology Research Institute on Taiwan, Xin-Zhu City, Taiwan, Sep.11, P.114.

Mathematical Formula  Min Z = Sj Aj Pj Oj Rj -1  where j is the j th robot arm,  k are the total number of robot arms.  s.t. Sj, Aj, Pj, Oj, Rj -1 > 0  It is the minimum sum of the free spaces, due date, processing time, occupied spaces and inverse of rotational spaces.

Property of Robot Arm  The robot arm dynamic layout problem involves the operational area.  The robot arm movable areas is triple than itself.  The set of robot arm is fixed to the floor.

GA approach (1) Solving the dynamic layout model is a NP-hard problem. A conventional optimization method is to reduce total flow cost (TFC). In the beginning, we separate the layout into a lot of grids. We choose one grid as the initial operation, and add the representation structure by stochastic operation. We will stop the structure until that there are no robot arm needed to assemble. A chromosome contains some operations and the length of a chromosome is a dynamic value which is determined by the robot arm jobs.

GA approach (2) Selection strategy is concerned with choosing chromosomes from the population spaces. It may create a new population for the next generation based on either parent and offspring, or part of them. For evaluating the fitness and reaching the objective, we calculate the summation of S.A.P.O.R -1. as a fitness function. Due to create the next generation, crossover and mutation are methods of trying to find a global optimal. We set the default value is that mutation rate is 80%, crossover rate is 50% and each of generation is 1000 times.

Feasible Solution Generation Procedure: A feasible solution generation Input: processing time, due date, length and width of robot arms, base set areas of robot arm, free spaces; While ( i < k ) do If there are no free spaces, then the sequence is finished: Stop. Else According to the due date, put the operation with the processing time. The array will remember those due dates, processing time and certain grids. If moveable area touch on the other base set areas of robot arm, then give up this operation. If when the operation is completed the processing and it goes within the due date, then we put a new time variable to represent it’s real processing time. If one job is finished, then to release the occupied and rotational spaces. Calculate free spaces; End while. Evaluate the S.A.P.O.R -1.; End procedure.

System Main Output

System Validation- Different Due Date

Conclusion and Suggestion  Layout on robot arm assembly factory is important to them.  Visual Basic 6 as a tool to draw the 2D pictures  We take the Borland C++ as a tool to compile the software to implement the GA approach.  Software would raise the utilities of the free space in factory and it take charge of production management progress effectively. Lower down the burden on factory personnel.  Suggest that combines BOM and ERP software