University:
California State University, Northridge
Course:
MSE 602 | Entrepreneurship and Innovation for Engineering Professionals
Academic year:

2024
Views:

195

Pages:

34
Author:

Purkw3n

Lean Operations: Process Synchronization and Improvement Lean Operations 1 Initiated by Japanese automaker Toyota. Adopted in USA by the aerospace industry in 1990’s Some turnaround times were lowered by 30-50%. Maintenance productivity improved by 25-50% Improved performance in all four dimensions in Plants and Supply Chains » Plant: any singly owned, independently managed and operated facility (i.e., manufacturing site, service unit, storage warehouse) » Supply Chain: a network of interconnected facilities with diverse ownership, and flows of information and materials between the facilities (i.e., raw materials suppliers, finished goods producers, wholesalers, distributors, retailers) Lean Operations: Process Synchronization and Improvement What is an Ideal Process? Synchronization + Efficiency 2 Process Synchronization: The ability of the process to meet customer demand in terms of their quantity, time, quality and location requirements. » Exactly what is needed (not wrong or defective products) » Exactly how much is needed (neither more or less) » Exactly when it is needed (not before or after) » Exactly where it is needed (not somewhere else) Process Efficiency: Measured in terms of the total processing costs. Less cost, more efficient!!. At the lowest cost Lean Operations: Process Synchronization and Improvement The Process ideal: Synchronization & Efficiency 3 Just-In-Time (JIT) » When the four “just rights” come together— » Action is taken only when it becomes necessary!!! » In Manufacturing - production of only necessary flow units in necessary quantities at necessary times!!! Synchronized Networks: » Outflow of one process is the inflow to another process!!!! » Requires precise matching of supply & demand » All stages are required to be tightly linked with flow of information and product » Ideally – the processing stages are achieved for lowest possible cost!!!! Lean Operations: Process Synchronization and Improvement Waste and Its Sources 4 ANYTHING LESS THAN IDEAL PERFORMANCE IS AN OPPORTUNITY FOR IMPROVEMENT!!! Low Efficiency = High Processing Costs Lack of Synchronization Defective products, high inventories, delays, stock outs Lean Operations: Process Synchronization and Improvement Buzz-words for managing and achieving efficiency within a plant Other names connected to lean operations; JIT production, Zero inventory program, Synchronous manufacturing, Agile manufacturing, Toyota Production System (TPS) 5 Lean Operations: Process Synchronization and Improvement Waste and Its Sources 6 Waste: producing inefficiently, producing wrong or defective products, producing in quantities that are too small/large, delivering early/late Sources of Waste: » Producing defective products » Producing too much product » Carrying inventory » Waiting due to unbalanced workloads » Unnecessary processing » Unnecessary worker movement » Transporting materials Lean Operations: Process Synchronization and Improvement Waste Reduction 7 Short term strategies: » Cycle & Safety inventories » Safety capacity » Non-Value adding activities (transportation, inspection, rework, process control) Long term strategies: » Improve the overall processes » Build in flexibility, predictability, stability to eliminate temporary fixes. i.e., Reduce setup costs to make it more economical to produce small batches. Lean Operations: Process Synchronization and Improvement The River Analogy 8 The boat can sail in shallow water (lean operations) if we are able to find ways to remove the imperfections on the river bottom!!! FM Defective Materials Long Lead Times Unreliable Suppliers WIP Machine Breakdowns Unsuitable Equipment Inefficient Layouts FG Defects Long Setups Uneven Schedules Absenteeism Rigid Work Rules Lean Operations: Process Synchronization and Improvement Four Objectives of Lean Operations 9 Improve process flows (Process Synchronization) – Efficient plant layout – Smooth flow of materials and information Increase process flexibility (Process Synchronization) – Low equipment changeover times – Cross-functional training Decrease process variability (Process Synchronization) – Flow rates – Processing times – Quality Minimize processing costs (Process efficiencies) – Eliminate non-value adding activities Lean Operations: Process Synchronization and Improvement Efficiency/Synchronization for mass production: Henry Ford’s Rouge, Michigan plant 10  Totally integrated with – steel mill, glass factory, machine tools, electrical systems, assembly line, well-trained (well-paid) workers  Minimal time & cost  Everything in place except product variety! Lean Operations: Process Synchronization and Improvement 10.4.1 Improving Process Architecture: Cellular Layouts 11 Process Architecture: the network of activities and resources One method: FUNCTIONAL LAYOUTS Different product types follow different routings through the resource pools…enabling each flow unit to be sent to any available station in the pool. Lean Operations: Process Synchronization and Improvement 10.4.1 Review of Process Architectures: Job Shop 12 Functional Layout: Resources that perform the same function are physically pooled together– JOB SHOPS Product 1 Input Product 2 A C Output B D Lean Operations: Process Synchronization and Improvement 10.4.1 Improving Process Architecture: Cellular Layouts 13 Alternate to Process-based Functional Layout: CELLULAR LAYOUT All workstations that perform successive operations on a given product are grouped together to form a “CELL” Lean Operations: Process Synchronization and Improvement 10.4.1 Improving Process Architecture: Cellular Layouts 14 Product 1 Input A B C Output Example: Henry Ford’s Assembly Line for the Model T Lean Operations: Process Synchronization and Improvement Improving Process Architecture: Cellular Layouts 15 + ADVANTAGES Facilitates synchronous flow of information and materials between processing stations Physical proximity of cells reduce transportation of flow units Moves small batches of flow units quickly Encourages teamwork & cross functional skill development + Improved communication between stations Improves synchronization where each station produces parts only if the next station needs them Easier to recognize and report problems Quicker ability to correct defects Lean Operations: Process Synchronization and Improvement 10.4.1 Improving Process Architecture: Cellular Layouts - DISADVANTAGES Resources are dedicated to specific cells Resources cannot be used by other cells Lose advantage of resource pooling Worker incentives must be “team” oriented, not individual performance based - REMEDIES: » Use flexible resources that are cross functional » Peer pressure to control productivity of team members 16 Lean Operations: Process Synchronization and Improvement Push Strategy 17 Push Production: Input availability triggers production where emphasis is on maximization of resource utilization (as long as there is work) » Planning Tool is Material Requirements Planning (MRP) » MRP: End-Product demand forecasts are “exploded” backwards to determine parts requirements at each station PUSH works well if and only if » All information is accurate » Forecasts of finished goods are correct » There is no variability in processing times Otherwise, it will disturb the planned flow, and destroy synchronization throughout the process!! Lean Operations: Process Synchronization and Improvement Pull Strategy 18 Push Production: Where demand from a customer station triggers production. Each station produces only on demand from its customer station The demand is actually “downstream” PULL works well if and only if » There is a well-defined customer/supplier process. » The process can produce the quantity needed only when signaled to do so by its customer Lean Operations: Process Synchronization and Improvement 10.4.2 Improving Information & Material Flow: Demand Pull 19 SUPPLY PUSH: Input availability triggers production Supplier Inputs Process Outputs Customer DEMAND PULL: Output need triggers production Supplier Information Flow: Inputs Process Outputs Material Flow: Customer Lean Operations: Process Synchronization and Improvement 10.4.2 Improving Information & Material Flow: Demand Pull 20 Demand Signaling: Customer needs a way to signal (inform) the supplier of its need. Customer’s demand starts a chain reaction – − For withdrawals and replenishments of intermediate parts − EOQ-ROP system is a “Pull” system where ROP triggers production at the supplier and EOQ determines the quantity produced Lean Operations: Process Synchronization and Improvement 10.4.2 Improving Information & Material Flow: Demand Pull 21 Synchronized Pull: When the delivery of parts are in sequence [Suppliers must have greater ability and capability to achieve a synchronized pull effectively] Lean Operations: Process Synchronization and Improvement 10.4.3 Improving Process Flexibility: Batch-Size Reduction 22 Each station must know HOW MUCH TO PRODUCE AT A TIME − Level Production: where small quantities are produced frequently to mach customer demand [i.e., if demand is 10000 sedans and 5000 SUVs, the production would call for producing 2 sedans and then 1 SUV, and then repeat the sequence] − Changeover Costs and Batch Reduction: Goal of level production is reduction of changeover costs (fixed setup or transportation costs of each batch) − I.E. In auto production expensive parts like seats are produced in batches of one, wipers in larger batches  Study the Changeover process to: use special tools to speed it up, customize some machines, keep some machines already set up.  Consider “small-batch” production Lean Operations: Process Synchronization and Improvement 10.4.4 Quality at Source: Defect Prevention & Early Detection 23 Defective flow units increase average flow time and cost!!! WHY? It necessitates inspection and rework!!! Anticipate and then Compensate for the problem: » Hold extra safety inventory in the buffer » This increases avg. flow time and cost Plan and control Quality: 1. Prevent defects for occurring in the first place 2. Detect and correct them as soon as they appear Lean Operations: Process Synchronization and Improvement 10.4.4 Quality at Source: Defect Prevention & Early Detection 24 Defect Prevention » Careful design of both product and process » Simplification & standardization » Mistake-proofing (poka yoke) − Parts are designed to halt automatically when defective units are fed into them (parts are designed to minimize chances of incorrect assembly) Defect Visibility » Early detection/corrections more effective & economical Lean Operations: Process Synchronization and Improvement 10.4.4 Quality at Source: Defect Prevention & Early Detection 25 Defect visibility (cont’d) » Early detection helps tracing to the source » Contribution to better synchronization and lower costs » Early detection requires constant vigilance and monitoring!! Decentralized Control » Employees must be empowered with authority and the means to identify & correct problems at the local level Lean Operations: Process Synchronization and Improvement 10.4.4 Quality at Source: Defect Prevention & Early Detection 26 Decentralized Control (cont’d) » In typical plants, line workers don’t feel the responsibility, motivation or security to point out problems. BEST STRATEGIES OF LEAN OPERATIONS ARE: 1. Preventing problems through better planning 2. Highlighting problems as soon as they occur 3. Delegating problem solving to the local level Lean Operations: Process Synchronization and Improvement 10.4.5 Reducing Processing Variability: Standardization of Work Maintenance, and Safety Capacity 27 Reduce Variability: » Standardize work at each stage and specify it clearly Advantages to Standardization: » Reduces variability from changing personnel » Reduces variability from one production cycle to the next » Makes it easier to identify sources of waste that can be eliminated Lean Operations: Process Synchronization and Improvement 10.4.5 Reducing Processing Variability: Standardization of Work Maintenance, and Safety Capacity 28 Lean Operations try to: » Minimize carrying safety inventory due to increased flow time » Maintain some safety capacity as production against variability − These could be extra machines, workers, overtime  These forms of safety capacity should be flexible so that it can be used as needed!! Lean Operations: Process Synchronization and Improvement 10.4.6 Visibility of Performance 29 A company needs to “see” (measure) process performance from the customer’s perspective » I.E. Time per call Measure Percentage of Customers that had a problem resolved with one call Actual performance (along with expectations) should be visible at each work cell Not for punishment, but to provide quick feedback for corrective action Lean Operations: Process Synchronization and Improvement 10.4.7 Managing Human Resources: Employee Involvement 30 SYNCHRONIZATION WITHIN A PLANT REQUIRES: 1. Cooperation 2. Contribution 3. Commitment Elton Mayo’s “Hawthorne Experiments” at Western Electric showed that: Research has shown that workers involved in the decision-making process are better motivated and productive Lean Operations: Process Synchronization and Improvement 10.4.7 Managing Human Resources: Employee Involvement 31 In Companies with Lean Operations: • Workers are cross-trained to provide the company with flexible workers. • Workers are in work teams in cells and may perform certain managerial duties such as material ordering, hiring, scheduling • Great importance on recruiting and training of workers Lean Operations: Process Synchronization and Improvement 10.4.8 Supplier Management: Partnerships 32 Outsourcing: Provides a flexible alternative to producing inhouse BUT- - - purchased materials account for a major portion of product cost and are a major source of quality problems!! Lean approach: » Choose only a few capable suppliers » Cultivate cooperative, long-term relationships Lean Operations: Process Synchronization and Improvement 10.4.8 Supplier Management: Partnerships 33 In Lean Operations: » Suppliers are an extension of the plant » Processing without inventories or quality inspection » Synchronization requires defect-free material » Frequent deliveries, small batches » Supplier’s process be able to produce small quantities on demand Lean Operations: Process Synchronization and Improvement 10.4.8 Supplier Management: Partnerships 34 YOU ARE TREATING THE SUPPLIERS AS PARTNERS

Lean Operations

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