PULL / JIT

PULL / JITLT6 Training Module

INTRODUCTION

What are Pull & JIT?

» An inventory strategy » Improves the return on investment

of a business by…– Reducing in-process inventory – Reducing cycle time

» Driven by signals, or Kanban, to…– Make the next part, or– Move the next part

INTRODUCTION

PULL/JIT| LT6 Training Module

» First used by the Ford Motor Company (early 1900’s)

– "dock to factory floor" – not stored in warehouse, on factory floor

» Adopted by Toyota as part of its Toyota Production System (TPS)» Little space for inventory» Required shortening Set Up Times, through

SMED» Changed assumptions about Economic Lot

Quantity (ELQ)» ELQ fell to 1 unit

» When a part disappeared, a signal to produce or order a replacement.

HISTORY


JIT AND PULL, related to……

WHY JIT & PULL


But why is it important?

WHY JIT & PULL


8 WastesDefects OverproductionWaitingNon-utilized talentTransportationInventoryMotionExtra processing

So…

What’s So Bad About Inventory?

Why Inventory?


It HIDES problems

Why Inventory?



Poor Quality

Work in process inventory level(hides problems)

Unreliable Vendors

Capacity Imbalances

Why Inventory?



ScrapUnreliable Vendors

Capacity Imbalances

WIP

Lower Inventory level to expose problems, then…» Work on problems by:

– Reducing variability– Eliminating waste– Streamlining production and material flows– Accurate information

JIT


So, Pull & JIT are……?

» A management philosophy of continuous and forced problem solving

» Supplies and components are ‘pulled’ through system to arrive where they are needed when they are needed

» Goal: Achieve the minimal level of resources required to add the necessary value in the production system.

» A means of making WASTE easy to see.

JIT


JIT Philosophy……

» JIT means the right quantity at the right place and the right time.

» Minimize or eliminate wastes (hidden rocks)

» Simpler is better» Focuses on improving all operations» Flexibility to produce different

models/features with minimal set up

JIT


JIT Elements……

» Inventory reduction - exposes problems

» Kanbans & pull production systems» Small lots & quick setups» Uniform plant loading (leveling the

load)» Flexible resources» Efficient facility layouts

JIT


JIT Objectives……

» To eliminate waste, by…..– Producing the needed item– at the right time– and the exact quantityAND….– When a problem is identified, fixing it

JIT


JIT Principles……

» Produce only what the customer wants

» Produce only at the rate the customer wants

» Produce with perfect quality» Produce with minimum lead time» Produce with no waste of labor,

material or equipment

» Produce with “flow”

Flow


What is Flow?

» One piece at a time, opposite of batching

» Minimal distance between operations» Small flexible equipment VS Large

inflexible » Cross Functional VS Departmentalized» Cross Trained operators, easily moved» Produce to the Takt, » Level Loaded production

Enablers


What ENABLES JIT to work» Quick set ups (SMED) » Stable processes» Use of standard containers » Doable stable schedules with adequate visibility» TAKT-Time» 5-S efforts » Kaizen Events » Visual controls » Flexible workers » Tools at the point of need » Products designed for manufacturing » Group Technology (product families)» Total Productive Maintenance» Kanban

Benefits


What kind of benefits can you expect with JIT?

» Smaller inventories» Shorter lead times» Quicker response to customer demand» Improved quality» Reduced space requirements» Lower production costs» Increased productivity» Greater flexibility» Lower inventory carry costs (%25)

Works Best


JIT works best when….

» Trust is present– labor/management– suppliers/consumers

» Individuals are familiar with problem solving» Quality at the source is emphasized» There is agreement over value and waste» Applied in the growth to maturity phases of Product Life Cycle » Products are somewhat “standard”» Standard/fixed pay-rate

– Problems with piece-rate systems» Universal agreement that change is needed

Key Enablers…


Quality at the Source

» For JIT to work, quality must be high– There should be no extra inventory to buffer against the

production or use of defective units

» Producing poor-quality items, and reworking or rejecting them is wasteful

» The workers must be responsible for inspection & production quality

» The philosophy is, “NEVER pass along a defective item

Key Enablers…


One Piece Flow, Continuous Flow

» The opposite of batch, lot, or mass processing» Product should move (flow) from operation to

operation, only when it is needed, in the smallest increment possible

» One piece is the ultimate (single-piece-flow)» Cross train operators

» Operators float to the bottleneck

Key Enablers…


Pull Production, an feature of JIT

» Actual customer demand drives the manufacturing process

» It creates a system of cascading production and delivery signals from downstream demand to upstream production in which nothing is produced by the upstream supplier until the downstream customer signals a need– Big Benefit – Schedule only one point the value stream

» The rate of production for each product is equal to the rate of customer consumption

Key Enablers…


Pull Example

Sub

Sub

Fab

Fab

Fab

Fab

Customer Request Final Assy

Vendor

Vendor

Vendor

Vendor

Production

Schedule

LeveledSchedule

A

AC

AB

Key Enablers…


Work Balancing / TAKT Time

» Work balancing maximizes operator efficiency by matching work content to TAKT time

» TAKT time is the rate at which customers require your product

» TAKT time is calculated as follows:

Available work time per day

Daily required customer demand in parts per day

Available work time per day

Daily required customer demand in parts per day

Simulation…


Let’s see how this works

» YESCO Aviation – Brand new operation– Building planes– 4 Assembly Operators– 1 Material Delivery– 1 Timer– 1 Customer– 1 Manager

Simulation…



» YESCO Aviation – Brand new operation– Customer watches for defects– Building and moving 3 at a time (ELQ)– Call Mtl Handler to move product– Customer will take all you can build– Don’t change layout– Colored paper will track “Lead Time”– Will run until enough work in process to capture data

Simulation…



» YESCO Aviation – How’d we do?Run #1 Run # 2 Diff

Lot SizeWIP

Lead TimeTotal Run Time 7.25 1.65 0.23

Deiveries 18 10 56%# of People 6 5 83%

SpaceProductivity 0.41 1.21 2.93

Defectives

Simulation…



» YESCO Aviation – Run # 2– Move however you like– Lot Size – 1

– Introduce Single Piece Flow discipline

» How’d we do

» Wrap up

Conclusion


What’s next?

» Ensure quality» Remove clutter & minimize storage» Reduce setup times» Level load orders, produce to takt » Implement layout changes

– Cellular manufacturing &/or close proximity

» Cross train and teach to float to the bottleneck» Move to pull production» Extend methods to suppliers» Review and improve

Conclusion


Q & A

PULL / JIT

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Transcript of PULL / JIT