160 likes | 339 Views
MODELING AND ANALYSIS OF MANUFACTURING SYSTEMS. Ernesto Gutierrez-Miravete ernesto@rh.edu RENSSELAER AT HARTFORD http://www.rh.edu/~ernesto/C_S2001/mams. PURPOSE OF MANUFACTURING. TO INCREASE SHAREHOLDER VALUE TO SATISFY CUSTOMER WANTS AT MINIMUM COST
E N D
MODELING AND ANALYSIS OFMANUFACTURING SYSTEMS Ernesto Gutierrez-Miravete ernesto@rh.edu RENSSELAER AT HARTFORD http://www.rh.edu/~ernesto/C_S2001/mams
PURPOSE OF MANUFACTURING • TO INCREASE SHAREHOLDER VALUE • TO SATISFY CUSTOMER WANTS AT MINIMUM COST • TO ENRICH SOCIETY THROUGH THE PRODUCTION OF QUALITY, LOW COST PRODUCTS WITH MINIMUM IMPACT ON THE ENVIRONMENT
MANUFACTURING SYSTEM FUNCTIONS • PRODUCT DESIGN • PROCESS PLANNING • PRODUCTION OPERATIONS (FABRICATION & ASSEMBLY) • MATERIAL FLOW/FACILITIES LAYOUT • PRODUCTION PLANNING/CONTROL • ADMINISTRATIVE
PURPOSE OF MODELING • TO HELP IMPROVE MANUFACTURE SYSTEM DESIGN. • TO HELP PREDICT MANUFACTURING SYSTEM PERFORMANCE. • NOTE: GOOD MODELING REQUIRES GOOD DATA!
MANUFACTURING SYSTEM TYPES • PRODUCT LAYOUT • Products move sequentialy along the same flow line • Examples: Assembly and Transfer Lines • PROCESS LAYOUT • Products move sequentialy visiting different workstations according to a plan • Examples: Job Shops
MANUFACTURING SYSTEM TYPES (contd) • CELLULAR (GROUP) LAYOUT • Similar parts are grouped together to justify their own machines • Roughly a hybrid of Process and Product Layouts • FIXED POSITION LAYOUT
CHARACTERISTIC FEATURES OF LAYOUTS • THROUGHPUT TIME (T) • PRODUCTION RATE (P) • WORK IN PROCESS (WIP) • SKILL LEVEL • PRODUCT & DEMAND FLEXIBILITY • MACHINE UTILIZATION • UNIT PRODUCTION COST
Question • How does the number of Parts per Hour vs. Number of Part Types vary with Layout type?
Little’s Law WIP = P*T Mass and Energy are Conserved Larger Systems are Less Reliable Law of Material Decay Complexity Growth NM Technology Changes Randomness of Behavior Limits of Rationality Combine, Simplify, Eliminate to produce Savings “LAWS” OF MANUFACTURING
MANUFACTURING MODELS • EFFICIENCY VS. EFFECTIVENESS • PHYSICAL MODELS • ANALYTICAL MODELS • PRESCRIPTIVE • DESCRIPTIVE • EXPERIMENTAL MODELS • SIMULATION MODELS • HYBRID MODELS
HEURISTIC APPROACH • AN ATTEMPT TO FIND A GOOD (i.e. NEARLY OPTIMAL) SOLUTION TO A PROBLEM BY USING A RATIONAL METHOD. • HOW TO SELECT WHICH INFORMATION TO IGNORE? • HEURISTICS VS. OPTIMIZATION
MODEL USES • OPTIMIZATION • PERFORMANCE PREDICTION • CONTROL • INSIGHT • JUSTIFICATION • MARKETING TOOLS
MODEL DEVELOPMENT • PROBLEM DEFINITION • DETERMINATION OF RELEVANT INFLUENCING FACTORS • MODEL BUILDING • VERIFICATION • VALIDATION
ASSIGNMENT • READ • CHAPTER 1 AND SEC 2.1 IN A&S • BROWSE AND EXAMINE • CHAPTERS 11, 12 AND 13 IN A&S • HOMEWORK • PREPARE FOR CLASS PRESENTATION THE SOLUTION OF ONE PROBLEM AT THE END OF CHAPTER 1