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Maintainability

An invaluable weaponin your relentless pursuit of improved equipment availability

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What is “Maintainability” anyway?

It is not Reliability

Reliability improvement seeks to increase the Mean Time Between Failure (MTBF)

Maintainability seeks to improve our response to an eventual failure: Mean Time To Repair (MTTR)

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What is “Maintainability” anyway?

Maintain-ability is a characteristic of a machine or process, encompassing:

Serviceability

Reparability

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What is “Maintainability” anyway?

It can be improved post-startup

Improved servicing

Improved repairing

•5-S•Poka Yoke•TPM•Lubrication TechniquesRCA

FMECA •Quick Disconnects•Jigs & Fixtures•Modular Design•Repair Plans•Troubleshooting Knowledgebase

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Why focus on in-service equipment?

Initial Procurement $

Equipment in Design

Capital Replacement Budgets

Skilled

Maintenance

Labor

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Why focus on in-service equipment?

Total Cost of Ownership Installed Base

Global Competition

Unskilled

Labour

Initial Procurement $

Equipment in Design

Capital Replacement Budgets

Skilled Maintenance

Labor

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Why focus on in-service equipment?

Installed Base

Global Competition

Initial Procurement $

Equipment in Design

Capital Replacement Budgets

Skilled Maintenance

Labor

Reality of Aging Infrastructure

Immediate Payback

Costs MUST be reduced to maintain margins

Need to find competitive advantage

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Why focus on in-service equipment?

Total Cost of Ownership

Unskilled Labor

Initial Procurement $

Equipment in Design

Capital Replacement Budgets

Skilled Maintenance

Labor

Looming Retirement Crunch

Low Rates of Apprenticeship

Estimated 5x to 10x Initial Equipment Cost

Frequently Hidden in “Overhead” – your

budget

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What is Mean Time To Repair?

Running as desired

Not running as desired“failed” “broken”

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What is Mean Time To Repair?

Defining MTBF “Uptime”

Total running time . MTBF =# Failure Events

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What is Mean Time To Repair?

Calculating MTTR “Downtime”

Total non-running timeMTTR =# Downtime Events

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What is Mean Time To Repair?

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

MTTR Breakdown

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A Maintainer’s Tale of A Maintainer’s Tale of Horror …Horror …

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4 Process

Lines

6 Packaging Lines

4 Robotic Palletizers

ONE Strapper-Labeler

I worked in a typical factory:I worked in a typical factory:

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First, something went wrong …First, something went wrong …

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• no indication of why the strapper wouldn’t work• no record of ideal machine settings

What’s wrong?

Dunno

Go fix!

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… … and we couldn’t get around it … and we couldn’t get around it …

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• couldn’t bypass the bottleneck• multiple trades needed to troubleshoot• lockout procedure slowed testing cycle

Fixed yet?

Nope

Keep at it!

What’s wrong?

Dunno

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… … and we weren’t sure of ourselves …and we weren’t sure of ourselves …

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• drawings and manual were back at the shop• no action plan – Troubleshooting Tunnel Vision!• could not predict when we would be done

Anything?

Nope

My boss is not happy!

I’m not happy!

What’s wrong?

Dunno

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… … and we didn’t know what to do …and we didn’t know what to do …

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• needed multiple tradesmen and tools• no SOP or time guidelines• high pressure from operations management

Get it done!

I’m working on it!

Anything?

I’m working on it!

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… … and at first, nothing worked … and at first, nothing worked …

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• spare unit was not ready• no offline test• no follow-up procedure

Almost done!

Nice knowing you.

Why did I hire you?

Why did you hire him?

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The final bill …The final bill …

Identify

Remove the

machine

Fix/install the spare

Test and re-start

Try to Fix

Time to Repair/Replace the Strapper

0....15….30….45.…60....75....90....105...120…135… minutes

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… … so can we really avoid this horror?so can we really avoid this horror?

Identify

Remove the

machine

Install the Spare

Test

Try to Fix

0....15….30….45.…60....75....90....105...120…135… minutes

135minutes

Original Design and Methods

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Time to Fight Time to Fight Back!Back!

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Improving "Maintain-ability"

Identify Failure Mode and Location

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• Use Visual Indicators• Label major components to reduce ambiguity• Use HMIs – get key information OUT of PLCs

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Improving "Maintain-ability"

Remove From Service

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• Build redundancy into key areas and bottlenecks• Install military-style quick disconnects• Support loads on sub-frames NOT on bolts

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Improving "Maintain-ability"

Planning and Preparation

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• Update and prepare drawings and parts lists• Use standard components• Make jigs and kits• Pitstop plan – operators and maintainers together• Pre-position key components

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Improving "Maintain-ability"

Execute Repair

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• Use air/power tools• Record what was done, good and bad• remember to keep failed parts for Root Cause Analysis• foster urgency without panic

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Improving "Maintain-ability"

Test and Return To Service

Identify

Plan/ Prepare

ExecuteRepair

Test/RTS

Remove from Service

• quality control – fix it right• reinforce teamwork with operations• document follow up work (repairable spares, PM improvements)

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There were many challenges …

Procedures

Design Tools

Skills

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… … we set an ambitious target …we set an ambitious target …

Identify

Remove the

machine

Install the Spare

Test

Try to Fix

Reduce the time from over two hours to less than 30 minutes

0....15….30….45.…60....75....90....105...120…135… minutes

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… … and exceeded it by far!and exceeded it by far!

Identify

Swap Components Test

0…. 2…. 4…. 6…. 8….1010

minutes

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What’s In It For Me?

Lots of focus (correctly) on Failure Prevention

When those efforts don’t yield sufficient results, improve maintainability

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Cost of Poor MaintainabilityCost Value

Idle Plant $1,000/hr

Breakdown Freq. 4/yr

MTTR 2 hr

Repair Labor 4 pers

Average Labor Rate

$35

Annual Breakdown Cost (labor

only)

$ 9,120

Cost Value

Electrical Parts $350

Mechanical Parts $150

Maintenance Labor $1,500 (overtime)

Investment Required: $2,000

Income Tax Rate 34%

Interest/Discount Rate 12.8%

Yr 1 Yr 2 Yr 3 Yr 9 Yr 10

Return $7,000 $7,000 $7,000 $7,000 $7,000

Depreciation $ 200 $ 200 $ 200 $ 200 $ 200

EBIT $6,800 $6,800 $6,800 $6,800 $6,800

Taxes $ 2,312 $ 2,312 $ 2,312 $ 2,312 $ 2,312

EBIAT $ 4,488 $ 4,488 $ 4,488 $ 4,488 $ 4,488

…

Reducing downtime from 2 hours to 30 minutes:About $7,000 saved in lost labor alone.

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The Payback:

Lessons Learned: Priceless

Payback Period: < 6 months You’re still

here!Thanks to you.

I’m confident in you.

Why aren’t you doing more of this?

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kaizen for Maintenance

Building a Virtuous Cycle

Improved Availability

Support for Maintainability

Increased Planning and Modification

Decreased Downtime

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The Maintainability Checklist

BASIC PRINCIPLES

Document parts and proceduresObstruction removalNo Tool ReplacementsTime Reduction without Panic

Build Pit Crew mentalityLoad bearing devicesIndicators and instrumentsNever just accept the current designKaizen!

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The Maintainability Checklist Document parts and procedures

Ensure drawings, flow directions, polarities, part numbers can be found by the right people when they need them

Obstruction removal Make critical components more accessible via access hatches, adding couplings,

etc.

No Tool Replacements Use high quality (like MilSpec) quick disconnects, install handles, build sub-

assemblies

Time Reduction without Panic Build and PRACTISE critical maintenance procedures

Build Pit Crew mentality Each team member knows what the other needs to do, and trusts them to do it.

This allows concurrent work to shorten repair times.

Load bearing devices A-frames, support rails, lifting beams and eyes

Indicators and instruments There are LEDs on everything these days, USE THEM. Install indicators where they

can be reached and easily read.

Never just accept the current design Builders are typically not maintainers, so have confidence that you have

knowledge that the OEM does not have.

Kaizen! Don’t rest, continue to learn and improve and learn again!

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So What’s Next?

If you encounter a recurring and challenging repair, you should:

Get Fired Up!

Get Better!

Don’t Blink!… any questions?

jerry_dover@hotmail.com

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Additional Resources

#1: YOUR SKILLED TRADES!

OEMs – newer designs, service technician experience

Government, especially Military (of course)

Heavy Industry – offshore oil, power generation, mining

http://www.cdc.gov/niosh/mining/pubs/pdfs/sp18-94.pdf