Unit 9 (2017)Apunte Inglés
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Unit 9: Just in time
How can we explain the Japanese success?
Selective personnel hiring
Promotion and evaluation policies
System of workstations rotation
Production equipment not overloaded
Clean and tidy work centres
Removal of nearly all inventories in productive plants
Maximum level of quality
Close relationship with suppliers
The fundamental objective is the increase of the company profit by reducing costs and taking
advantage of the resources available in the organization. Moreover, it removes unnecessary
costs and production must adapt to market demand changes, flexibly and early, without
JIT is a new perspective in operations managements that intend customers to be served - Just on the right time The required quantities Maximum products quality The production process uses the minimum inventory so that unnecessary costs are avoided.
Thus, JIT is a business philosophy.
Basic strategies - Removal of all unnecessary functions in industrial operations.
Production of the right quantity of elements that are required on a precise moment.
The five zeros Problems are hidden by stocks - Brokerage of stocks Lack of capacity Lack of quality - Uncertain demand Brokerages Basic tools - Balancing of production Kanban system Reduction of machine setup times and production times Standardization of operations Shojinka: Adaptation to market demand through flexibility Soikufu: Collection and better use of ideas and suggestions from the workers to improve operations and productivity.
Jidoka or autonomous defects control Total productive maintenance Relationship with customers and suppliers Balancing of production Certain productive processes require quantities and irregular time intervals→inventories.
Hierarchic perspective: - Master production schedule (MPS) Materials Planning (MRP) Operations scheduling Daily average rate of production A. Pull system B. Push system Kanban system It’s a pull system based on the usage of cards that manage and control the production in different work centres. It is necessary: - Flow diagram Warehouses Each item has its own mailbox There are two types: A. Transport Kanban Necessary information: Identification of transported item: Code and description Container capacity Order number of the card and number of cards issued Origin of the piece: Process and collection point Destination: Work centre and storage point B. Production Kanban Necessary information: Identification of transported item: Code and description Identification of work centre where the item is manufactured and place to store finished items Container capacity Identification of necessary components: Codes and collection points Advantages: - Production orders are always the same cards.
Each operator can only process the pieces that will be delivered to the following process. Then, the production of each moment equals the real needs of this moment.
Problems can be detected easily when inventories are reduced.
The level of inventories can be controlled through the number of cards.
Machine setup and production times Production time is made of: - waiting time between processes transport time productive time of the lot Lot sizing Single Minute Exchange of Die (SMED) Steps to improve machine setup times: - Distinguish between internal and external preparation.
Separate internal and external preparation.
Internal preparation --> external Operations standardization It determines the operations sequence that should be performed by a polyvalent operator so that: - Removes useless tasks or movements.
Balances processes in terms of production time.
Uses the minimum quantity of orders in progress.
There are three basic elements: - Production cycle of an item.
Standard sequence of operations of a worker.
- Standard quantity of orders in progress.
Shojinka Capacity to adapt to market demand through flexibility U shape distribution: - Operators can access to several machines.
Reduction of material of orders in progress.
Easy visual inspection.
Reduction of machine setup times.
Easy communications and mutual help among operators.
Task rotation: - Rise of motivation and monotony reduction.
None of the workers feels annoyed by the tasks assignment.
Mutual help processes are encouraged.
Stronger sense of responsibility of workers.
Soikufu Collection and better use of ideas and suggestions from workers.
Operators are the people that know better the different operations of the production process. Moreover, tasks are enriched by avoiding their useless and harmful aspects. There are suggestions plan and quality circles Jidoka Autonomous defects control Quality is a fundamental element. But is not controlled; it is manufactured. Using statistical control methods is not adequate. There is warranty to inspect 100% of manufactured pieces.
It has auto-inspection and “Poka-yoke” is a system that avoids errors automatically.
Total productive maintenance All the workers are involved in prevention, detection and correction tasks concerning design defects or machine performance errors. This has 2 fundamental advantages: - Operators are the people that know better the machines (noises, vibrations,…) Operators have a property feeling over machinery and consequently, they feel more responsible in case of a breakdown.
Relationship with suppliers Application of JIT to service industries - Synchronization and balance Flexibility Respect for the human resources of the company Continuous improvement of the process.
Cleaning attention Operations flow simplification Review of equipment and technological processes.
Production balancing Changes in layout distribution.
JIT implementation Previous step: Management training and creation of the implementation team.
Once you have applied this previous step you can proceed with: - JIT training for staff Process improvement Control improvement Relationships with suppliers and customers Variable Quality Maintenance Design changes Delivery terms Suppliers Planning Simulation Stocks Lot size Delivery terms Setup lines Workers JIT Objective: Zero defects Personnel responsibility Constant and effective Process and layout change In terms of hours Few and close to factory with long term relationship Pull type No simulation Hide problems.
Minimum level Objective: Small lots Reduction is fundamental Reduction is fundamental Important resource of company.
Strong collaboration MRP No management of quality statistics’ process control If necessary No changes In terms of weeks Traditional perspective: Many and short term relationships Push type Simulation through planning A certain level is maintained for protection.
Reduction is recommended Determined by many techniques Accepts present delivery terms Accepts present setup times Less participation ...