Apogee Mirror

Introduction

Pressure from customer to

Lower prices Higher quality More frequent deliveries Rapid response to change in demand

With value stream mapping improved:

Uptime Set-up time Continuous flow Throughput & inventory Did NOT want to modify the

information management system

Remaining problems: BOX SCORE

Need for overtime Expediting shipment to meet customer requirement Inventories were still high Production schedules need revision / unorganized Kaizen wore off, no JIT

Traditional Scheduling in Lean Facility

MRP weekly schedule has only limited resemblance to daily release from customer

o Wrong items are producedo Downstream processes lacks certain partso No way to implement JIT

Production capacity is greater than average demand Variation of demand: variation of family of products vs. part numbers

The Need to Switch from Erratic Push to Level Pull

Using forecast scheduled to push products accumulation of inventory

Cognitive instead of reflexive

Need to level and smooth external customer order level pull

Sufficient Stability

Must have uptimes of 75-80% if not use point and flow kaizen

The Transition Team Leader from production control One manager from every area of the operation Small staff who worked on the implementation

Matching Production-System Capability to Demand

Two cells were used to meet the volume requirements for exterior mirrors of left and right side mirrors.

Large buffers of finished goods for every part still wasn’t enough and overtime was used

The major challenge in this situation is for the downstream processes to obtain precisely what they need when they need it, while making upstream activities as efficient as possible.

(1) Process kaizen (point kaizen), such as setup or changeover time reduction at a certain workstation

(2) flow kaizen, which addresses waste reduction within a value stream, and (3) system kaizen, with a focus on expanding the improvement efforts across the

different value streams. In lean manufacturing, kanban is the specific tool for controlling information and regulating materials conveyance between production processes.

Enables JIT Kanban instead functions as a physical schedule tool

Kanban instead combines control over movement of material with respect to both time and quantity dependent upon signals from the downstream process.

Purpose of Kanban

There are four major purposes of kanban:

Prevent overproduction (and overflow) of material between production processes.

Provide specific production instructions between processes based upon replenishment principles.

Serve as a visual control tool for production supervisors to determine whether production is ahead or behind schedule.

Establish a tool for continuous improvement.

Kanban:

Q1. Which products to hold in a finished goods inventory and which to produce to

confirmed order?

ABC production analysis

Deciding about Finished Goods vs. Make-to-Order Which products to hold?

Q2. How much of each product should you hold in finished goods?

Average demand per day –using a three-month time span, Cycle stock: how much should be in the inventory to account for the lost

in time a part. Buffer Stock: If there is a surge in demand; using standard deviations. Safety Stock: shortfall in production from downtime or quality losses. =

scrap + rework

Q3 How to organize and control the finished-goods store?

Place finished good items on shelf after scanning – disrupted FIFO VISUAL CONTROLS & WORKPLACE ORGANIZATION

o Signageo Shelf allocated for old productso Spreadsheet for finished goods inventory.o Each part number is divided into 3 categories: cycle, safety and buffer

stocko Authorization is required to touch safety and buffer stock

Inability to ship on time Where to schedule the value stream How to level production at this location How to convey the demand to this location. Controlling production

throughout the plant

Q4. Where to Schedule the Value Stream?

MRP needs to be continuously updated MRP can be used for:

o Bill of Materialo Rough Cut Capacity Checko Forecast informationo Tasks in production planning

Guidelines fir selection of a pacemaker process

o A & B follows replenishment pull, so final assembly is the pacemakero Have a inventory for part C before assembling

Q5. How will you level production at the pacemaker?

Point efficiency at each process step was producing much larger system inefficiency in the form of inventory carrying costs, space requirements, expediting of missing parts and general management overheads.

Work content differences between products

Work content is varied by a small amount No product has work content above takt time

Changeover requirements between part numbers

Changeover times to zero

Production pitch interval

Q6. How to convey demand to the pacemaker to create pull?

The use of Kanbanso Use of Heijunka box

Conveyance operator who picks up products and places kanbans Determining a conveyance route of 6mins 10 sec and

having a pitch of 9 mins, often nothing was available to pick up so the pitch is increased to 18mins so that products can be picked up.

Pitch:o Creates continuous flowo See if production is keeping up with schedule

Alternative heijunka Methods

Use withdrawal kanbans in market which prompts production kanbans

Controlling Production Upstream

Q7. How will you manage information and material flow upstream from pacemaker?

This is due to the conflict between push and pull system

Create controlled markets fort A,B & C to buffer the flow and use withdrawal kanbans to regulate the movements of parts between these markets and the assembly cells.

o Spreadsheet listing every part used to assemble exterior mirror –Plan for every part

Move Material to Centralized Market Area and test conveyance route to the pacemaker.

Q8. How will you size your markets and trigger withdrawal pull?

Withdrawal Kanbano What to deliver to assembly area

To successfully trigger pull

A. Set a standard amount of inventory of each part to hold at the assembly cells based on the nature and frequency of the conveyance route

Use of small bins

They calculated that about 10 containers would be required by the two cells every 15 minutes and calculated that this would require 7 minutes and 50 seconds of work in addition to the four minutes of travel time between the parts market and the cells.

With a 15-minute route, Apogee could store as little as 30 minutes of inventory at the assembly cells—far less than they had in the past.

Next Apogee determined what one hour of material equated to for every part number at the cell. For some items it was one container (e.g., fasteners) and for others several containers.

With a 15-minute route, Apogee could store as little as 30 minutes of inventory at the assembly cells—far less than they had in the past.

B. Create a separate withdrawal kanban for each container stored at the cells.

Apogee’s exterior mirror parts withdrawal loop consisted of 30 different part numbers with one hour of inventory for each resulting in one to six containers for each stored line side.

The total number of withdrawal kanban in the loop for the exterior mirror cells was 110 cards.

C. Determine the right amount of inventory to hold in the central market.

Q9. How will you control batch processes upstream from the pacemaker?

Schedulingo Batch process with signal kanban

EOQ to determine the efficient size to run in production but this based on machine utilization which minimized the number of changeover.

o Sequence signal Kanban Determining time available for changeover work Set the number of changeover per day

o include downtime, divide by changeover timeo Determine the maximum number of changeover

permittedo Determine the production lot size

Fixed-time-variable-quantity method -based on demand for each part

Running the same fixed quantity of parts for each part number run

o Specify a trigger point for reorder

The longest replenishment time for machine # 4 therefore is 404 minutes, since that is the longest lead time possible before replenishment of the next part number can begin.

Q10. How will you expand your level pull system across the facility? Through all value streams in the company

value-stream rollout

o Since the exterior-mirror value stream improvement effort had taken approximately eight weeks to date and much of the elapsed time was learning the logic of the new system, they assumed the remaining value streams could be accomplished in no more than four months (for a maximum implementation time of six months).

departmental rollout

o Other members of the team instead proposed a departmental rollout, converting all the batch processes, then attacking all the remaining assembly cells and finished-goods areas at once, and finally targeting the central markets. Both approaches have their merits, as summarized in the table below.

Apogee chose departmental rollout approach because it would:

o Prevent some machines, such as molding, from being pushed on some part numbers while being pulled on others.

o Allow the team to immediately address the big problem areas of supplying material from molding and paint to assembly and quickly help improve on-time delivery to customers.

o Make it possible to combine material handling across cells and value streams, capturing full benefits more easily.

Q11. How will you sustain your level pull? Monitoring

o Customer demando The amount of inventory to holdo Average demand change

Assessments of performance metrics: scrap rates, changeover time and downtime

o Who is responsible?o How often do you need datao What process is not stableo What needs improvement –point kaizen

Daily supervision

o Is production ahead or behind schedule? o Are inventory levels above or below normal? o Are machines producing to cycle time? o Is assembly producing to takt time? o Do we have the right number of resources in place? o Are defects occurring and escaping downstream? o Are suppliers delivering on time?

Q12. How will you improve your level pull system?

Apogee will need to target and reduce safety-stock inventory through a series of targeted kaizen efforts. Apogee should focus on:

o Reducing scrap and rework in the paint department, specifically the problem of inclusions (small particles adhering to the paint).

o Eliminating equipment downtime in molding, paint, and final assembly, specifically minor mechanical downtime related to limit switches and sensors.

o Eliminating delays caused by material-handling problems between processes, specifically between the producing departments and the central markets as well as between central markets and final assembly.