Manual Material Handling and Ergonomics… Two Auto Assembly

Case Studies

CCOHS / CRE-MSD MMH Workshop

March 4, 2008

Wyatt Clark, CAW National Ergonomic Coordinator / Chrysler

Objectives

1) Overview of systemic MMH barriers to ergonomic interventions in the auto industry.

2) Two quick Case Studies of ergonomic “solutions” to some systemic MMH problems

3) Some discussion around how we “Get ‘Er Done”

4) Q&A

Systemic MMH Problems

• Vast majority of MMH barriers have TWO basic driving forces with each of those having a couple of complicating factors

1. Racking / bin design• Who owns the racking?• Transportation

Load density or ‘cubing’ of trucks

2. Real Estate1. Drives capital and fixed costs2. Affects productivity

Case Study 1 – General Part Delivery and Supply

• History lesson– The Old Days: parts arrive by truck in racks or bins

where they are unloaded by jitney and delivered directly to the assembly line or storage.

– The Not-So-Old days: JIT or Just In Time delivery attempted to solve real estate problems

– Today:• Small Lot Containers… an addition to JIT to squeeze more

real estate out of the system• More parts than ever are being shipped in including entire

subassemblies

Case Study 1 – General Parts Delivery

43”

18.5”

New problems Small lot delivery

adds a new level of human interface to a process done previously by machine

Some small lots can still have significant weight

How will this be managed?

Case Study 1 – General Parts Supply

Case Study 1 – General Parts Supply

New problems Small lot presentation lends

itself to an increased vertical configuration

Shelving creates hand access constraints

Have we simply shifted from a world of back postures to one of shoulder concerns

How will this be managed?

Case Study 1 - Final Resolve• Ergonomics involvement led to:

– Shelf height guidelines were determined based upon internal benchmarking and container sizes were standardized

– Recommendations provided for:• Generally:

– Totes to be loaded within a 30 lb target– Totes requiring loading beyond 30 lb target automatically trigger further

ergonomic analysis• Delivery Side (delivery dolly & gravity feed racks)

– Dolly shelves to be located at 19” and 43”– Dolly shelves to be no deeper than 25”– Maximum rack loading height is 62 in.– Totes which weigh >25 lb should be delivered to shelves no higher than 40” from

the standing surface• Supply Side (gravity feed racks)

– Assembly operator interface should be tiered ‘away’ to facilitate easy hand access to tote parts

– Bottom rack level is reserved for empty tote return only

Case Study 1 – Special Situations

Case Study 2 – Exhaust Assemblies

Case Study 2 – Exhaust Assemblies

• Problem– Reaches are unacceptable under ergonomic

guidelines– The repetitive back postures to accomplish all

the vertical lifting were problematic– Lack of foot clearance compounds both the

above

Case Study 2 – Exhaust Assemblies

• Solution 1– Easy… redesign the rack!– Sorry… can’t be done!– Why?– The supplier owns the racks.

• Solution 2– OK… Easy… re-rack the parts in our own rack design– Added bonus… can schedule the exhaust assemblies

while re-racking• Minimizes long ‘carries’ of heavy parts• Saves real estate• Saves walking time

Case Study 2 - Final Resolve

Case Study 2 - Final Resolve

Case Study 2 - Final Resolve

• Ergonomics joint involvement led to:– New rack design and incorporation of a lift table for in-plant parts

presentation

• Exhaust assemblies are trucked from supplier to TDF Inc. where they are unloaded, re-racked in sequence, re-loaded and trucked to the assembly plant.– Pros

• New racks resolve ergo hazards• Sequencing allows

– Increased productivity… less walking– Decreased real estate needs

– Cons• Ergonomic hazards were simply transferred to TDF Inc. workers

Get ‘Er Done

• What negotiations were required to achieve the ergonomic resolves in the two case studies?

• Short answer – None!

• You don’t ‘negotiate’ unsafe… you solve it.

• Why don’t we negotiate?

Get ‘Er Done

• Part of the answer is legislation and part of it is contract.– Legislation by way of the H&S Act requires

joint participation– Unions have always desired some control

over their work environment and the decision making that goes on within it and have used labour contracts to achieve varying degrees of that.

• Part of the answer is “economies of scale

Get ‘Er Done

• In relative terms though, those things are the easy part… they simply create opportunities, nothing else

• The real answer to our question of “Why” is “Credibility” – the credibility of the people and processes involved our ergonomic program

Get ‘Er Done

• Now, if that’s all psycho-bable to you, try “cost / benefit”. Make the business case… works every time!!!

Thank-You

Q&A