Three primary steps in maintenance reliability engineering

Three Primary Steps in Maintenance

Reliability Engineering

by Jim Taylor, CPE, CPMM

Director of Operations, Machinery Management Solutions, Inc.

www.machineryhealthcare.com

http://www.machineryhealthcare.com/


Key Takeaway: Reliability Engineering can be done by the

average maintenance professional

michaelcardus

You work in a small to medium size facility or plant.

California Cthulhu

You’re a Maintenance professional: an Engineer, a Maintenance Manager, Supervisor, Planner, or Crafts Person.

theakshay.

http://www.flickr.com/people/akshay012/

Low availability and repeat failures on your HVAC equipment is affecting your production and

customer service.

mlinksva

You want to either remove or detect failure causes to

manage the failures.

Goal

Managed

Avoided

Surprise Managed

Avoided

Surprise

Reliability Engineering principles provide a way to do that.

Measure Availabilit

y

FindBad

Actors

Perform Failure

Analysis

Develop Job Plan

Data Collection

Implement Job Plan

Repeat

One of your primary duties is

to improve Availability (Ao).

MTBF

MTTR

MLDT

FRACAS

What is Ao?

MLDTMTTRMTBF

FMTBAo

Availability is the proportion of time a system

is in a functioning condition

To do that you must increase

Mean Time Between Failures

(MTBF)

Czarcats

What is MTBF?

Average elapsed

time between failures

of an operating system

How do you calculate it?

Failures

HoursOperatingMTBF

_

Timeline from Wikipedia

How can you use it?

High MTBF can result from:

Design

Lack of training

Lack of proper tools

Lack of documentation

Lack of proper equipment

Lack of proper maintenance

Lack of proper parts

You also must reduce Mean

Time To Repair (MTTR)

B Rosen

What is MTTR?

Average time required to repair a failed component or system.

A measure of maintainability


Failures

hoursrepairtimeActiveMTTR

__

How can you use it?

High MTTR can result from:

Design

Lack of training

Lack of proper tools

Lack of documentation

Lack of proper equipment

You also must reduce Mean

Logistics Delay Time

(MLDT)

zyphbear

What is It?

Average time a system is

awaiting maintenance


Total delay time does not include active maintenance time

Failures

timedelayTotalMLDT

__

How do you use it?

High MLDT can result from:

Time for locating parts and tools

Delivery time

Locating, setting up, or calibrating test equipment

Dispatching personnel

Reviewing technical manuals

Awaiting transportation

To keep track of it all you need a

Failure Reporting, Analysis, and

Corrective Action Reporting System

(FRACAS).

English106

You must capture the details of the failure in enough detail to do effective failure analysis.

As found condition

Failed components

Operating parameters

Sequence of events

Fluid levels

Signs of over temperature or pressure

You must capture the times involved in order to calculate MTBF, MTTR and Ao.

Loading time = total time – planned downtime

Planned downtime = scheduled maintenance time + management time

Operation time = loading time – Unplanned downtime

Unplanned downtime = logistics delay time + active repair time

The data you capture must be stored in a way to make analysis as easy as possible.

fo.ol

After you have started collecting the data,

you are in a position to do Root Cause Failure Analysis

(RCFA).

www.isixsigma.com

For each problem, you

will find the cause,

the cost,and

a solution.

Determine the failure cause or causes?

brendan.wood

http://www.flickr.com/photos/brendanwood/

Define the effects of the failure and their costs.

Julia Manzerova

Unhappy Customer

Then rank the causes.

www.sixsigmaspc.com

Finally apply Reliability Centered

Maintenance (RCM) principles to

develop a corrective action.

You can use the RCM decision

tree to decide on the correct procedure.

Start at the top of the tree, assuming that the failure has occurred.

Develop & scheduleCondition Monitoring

task.Develop & schedule

PM task.Redesign system

or accept risk. Run-to-Fail

Will the failure havea direct and adverseeffect on safety or

environment?Will the failure have a

direct and adverseeffect on operations(quantity or quality)?

Will the failure result inother economic loss(high cost damage tomachines or system)?Is there an effective

Condition Monitoringtechnology/approach?

Is there an effectivePreventive

Maintenance task?

No

No

No

No

No

Yes

YesYes

Yes

Yes

3tr

ee

.vsd

Candidate

For -

As you can see, the decision tree is biased towards Condition Assessment.











Maintenance task?

No

No

No

No

No

Yes

YesYes

Yes

Yes

3tr

ee

.vsd

Candidate

For -

You may find redesign is best option in some cases.











Maintenance task?

No

No

No

No

No

Yes

YesYes

Yes

Yes

3tr

ee

.vsd

Candidate

For -

Make sure the procedure is both

effective and applicable.

An Applicable procedure

actually improves the situation.

An Effective procedure

costs less to do the procedure

than to suffer the failure.

Develop a corrective action plan in enough detail to enable

effective application.

The Job plan should have step by step actions.

Make sure you include all safety information.

Estimate all the resources needed.

You now have a Job Plan that should either eliminate the cause of the failures or give you

enough lead time to manage the failure.

We started with a piece of HVAC equipment that was causing problems.

mlinksva

We applied some basic RE principles to find the cause and develop a solution.

Measure Availabilit

y

FindBad

Actors

Perform Failure

Analysis

Develop Job Plan

Data Collection

Implement Job Plan

Repeat

We now must put that Job Plan into action and track the results.

We should see an increase in Ao and a decrease in costs.

Goal

Managed

Avoided

Surprise Managed

Avoided

Surprise

Key Takeaway:You can perform this kind of analysis.

theakshay.

http://www.flickr.com/people/akshay012/

Do it and you’ll avoid surprises, and you’ll have a happy customer.

Muffet

http://www.flickr.com/photos/calliope/136335411/

Within the next week pick a problem machine;Estimate the MTBF, MTTR, MLDT and availability, based on either history or subjective analysis. Pick a failure that is causing problems and perform a RCFA. Develop a way to manage that failure using RCM principles. Make sure the solution is both applicable and effective. Write and implement a Job Plan to correct the problem.

I’ll be glad to review your project if you’d like.

Your Next Step (Homework)

Questions?Comments?

Jim Taylor, CPE, CPMM

[email protected]

765-366-4285

http://blog.machineryhealthcare.com

mailto:[email protected]


Three primary steps in maintenance reliability engineering

Business

Transcript of Three primary steps in maintenance reliability engineering