JIT terms and concepts

Uniform production

. Smooth production requirements . Smooth demand across planning horizon . Use mixed-model assembly to steady component production . Use visual system to manage product movement . Can handle up to 10% change in demand

Lean Operation

A flexible system of operation that uses considerably less resources than a traditional system Tend to achieve Greater productivity Lower costs Shorter cycle times Higher quality

JIT II

A supplier representative works right in the company's plant, making sure the quality and supply of the items are appropriately supplied

Pull system (Just-in-Time)

A workstation pulls output from the preceding workstation as it is needed Output of the final operation is pulled by customer demand or the master schedule Pull systems are not appropriate for all operations Large variations in volume, product mix, or product design will undermine the system

Ultimate Goal

Achieve a system that matches supply to customer demand; supply is synchronized to meet customer demand in a smooth uninterrupted flow

Cost Accounting

Activity-based costing Allocation of overhead to specific jobs based on their percentage of activities

MPC: Limited WIP

Benefits of lower WIP What is WIP? Work-in-Progress All of the inventory that is not started or completed Small Lot Sizes Lowers WIP Lower carrying costs Increased flexibility Aids scheduling Saves costs of scrap and rework if there are design changes Lower cycle-time variability

Poka-yoke (Fail Safing)

Building safeguards into a process to reduce or eliminate the potential for errors during a process Examples Electric breakers Seatbelt fastener warnings ATMs that signal if a card is let in a machine Designing parts that can only be assembled in the correct position

Kanban

Card or other device that communicates demand for work or materials from the preceding station Kanban is the Japanese word meaning "signal" or "visible record" Paperless production control system Authority to pull, or produce, comes from a downstream process. Two main types of kanbans: Production kanban (p-kanban): signals the need to produce parts Conveyance kanban (c-kanban): signals the need to deliver parts to the next work center.

Personnel/Organizational: Continuous Improvement

Continuous improvement (Kazien) Workers in lean systems have greater responsibility for quality, and they are expected to be involved in problem solving and continuous improvement Lean workers receive training in Statistical process control Quality improvement Problem solving

Building Blocks: Personnel/Organizational

Five personnel/organizational elements that are important for lean systems: Workers as assets Cross-trained workers Continuous improvement Cost accounting Leadership/project management

Process Design: Small Lot Sizes / Level Loading

In the lean philosophy, the ideal lot size is one Benefits of small lot size Reduced in-process inventory Lower carrying costs Less storage space is necessary Inspection and rework costs are less when problems with quality do occur Permits greater flexibility in scheduling Less inventory to 'work off' before implementing product improvements Increased visibility of problems Increased ease of balancing operations

Close Vendor Relationships

Lean systems typically have close relationships with vendors They are expected to provide frequent, small deliveries of high-quality goods A key feature of many lean systems is the relatively small number of suppliers used A fewer number of suppliers is preferred to emphasize quality and relationship building

Small lot production

Less space Less capital investment Less inventory Moves processes closer together Makes quality problems easier to detect Makes processes more dependent on each other

Seven elements of manufacturing planning and control (MPC) are particularly important for lean system:

Level loading Pull systems Visual systems Limited work-in-process (WIP) Close vendor relationships Reduced transaction processing Preventive maintenance and housekeeping

MRP (Push)

Lot size or batch production Extensive shop floor control More complex Relies on computer system to trigger production and order inventory (anticipates demand, pushes inventory to consumer) Inventories related to batch or lot sizes

Strategies For Eliminating Waste

Manufacturing in smaller lot sizes reduces excess inventory

facilities layout & process flow

Minimize movement of parts Balanced workstation capacities Flow efficiency Small lot sizes Reduced setup/changeover time

A balanced system

One that achieves a smooth, rapid flow of materials and/or work through the system

Total Productive Maintenance (TPM)

Preventive maintenance Maintaining equipment in good operating condition and replacing parts that have a tendency to fail before they actually do fail Housekeeping Maintaining a workplace that is clean and free of unnecessary materials

Process Design: Quality Improvement

Quality defects during the process can disrupt the orderly flow of work Autonomation (jidoka) Automatic detection of defects during production Two mechanisms are employed One for detecting defects when they occur Another for stopping production to correct the cause of the defects

JIT (Pull)

Repetitive production Minimal shop floor control Simpler Relies on visual or audible signals to trigger production and inventory (reacts to demand, inventory is pulled by customer orders) Lower inventories related to need "at the time"

JIT

Simply put, JIT is a philosophy of "make what is needed ... when it is needed". Management philosophy (produce only what is needed when it is needed) . Pull system (demand pulls supply is a manufacturing philosophy involving an integrated set of procedures/activities designed to achieve a high volume of production using minimal inventories (raw materials, work-in-process, and finished goods).

JIT requires

Standardization of product design refers to the absence of variety in products/services . interchangeable parts, modular design (fewer items) . reduced time for training workers . may require less effort (purchasing, facilities, inventory management) Design simplification (original design, revised design, final design)

Process Design: Balanced System

Takt time A method used to balance cycle time by producing small and equally spaced items per each manufacturing cycle Sometimes referred to as the heartbeat of a lean system Takt time is often set for a work shift Procedure: Determine the net time available per shift If there is more than one shift per day, multiply the net time by the number of shifts Compute the takt time by dividing the net available time by demand

Vendor Managed Inventory (VMI)

The manufacturer shares daily consumption / use data to the supplier who is responsible for managing and delivering the right amount of inventory when needed

Push System

Work is pushed to the next station as it is completed and manufacturing quantities are planned in anticipation (in advance) of actual demand

concurrent engineering

old, improved- all functions form a design team that develops specifications