“Machine failure is not an event, it’s a process”

• Emerging new technologies are able to extend the useful life of a machine with added intelligenceSensors

• Ultrasonic sensor technology is used as a “computerized stethoscope” providing access to another dimension in machine health

– Stress

– Friction

$$

CO

ST

& T

IME

FO

R R

EP

AIR

S

INCREASING SEVERITY OF DAMAGE

• Lubrication degradation• Minor surface defects

• Bearing spalling• Loose particulates

• Heating/friction

• Cracked parts• Damaged teeth

• Pitting of surfaces• Abrasion

$ HUNDREDS

$ THOUSANDS

$ 10xTHOUSANDS

Asset life expectancy

Damage to asset

•Turn shafts• Replace bearings

• Replace gears

• Align shafts• Replace bearings• Purge particulates

• Change lubricant• Pack bearings

$ 100xTHOUSANDS

• Replace machine• Major outage• Plant damage

• Major wear/damage• Misalignment• Bent shafts

• Broken parts

NEW TECHNOLOGY & DATA FUSION

TRADITIONAL TECHNOLOGY

Getting Ahead of the Curve

Smoke Alarm

“Machine failure is not an event, it’s a process”

• “Data Fusion”… combining intelligent machine data, process data and maintenance planning data to access operations effectiveness and efficiency.• reduce false alarms• continue to evolve best operating practices• Information interaction and visibility which results into real time data

availability

Improved decision support and risk analysis

Failure, Nature & Characteristics

• Critical Failure.• If a system is totally incapacitated such that there is a complete loss

of function (total loss of function)

• Degrade Failure.• If a system, despite failure, can still be of use so that it has partial or

degraded functionality (where the loss is partial)

• Evident Failures.• Deterioration in condition of equipment is known to the operator

• Hidden Failures.• Failures are unknown to the operators during normal operation• These failures are observed with proactive instruments

Failure, Nature & Characteristics

• Incipient Failures.• If the deterioration process is gradual, and takes place over a

period of time, there is a point where we can notice the start of deterioration

• Incipiency is the point at which onset of failure becomes detectable• There comes a point when the performance is no longer

acceptable. This is the point of functional failure• The incipiency interval is thus the time from onset of incipiency to

functional failure• When the failures are evident & exhibit incipiency, it is possible to

predict the timing of functional failures

• Operating Context • Failures also happen due to lack of skill, trg, motivation, morale,

sense of being wanted & being treated fairly

Failure Analysis

• Several types of failure analysis systems exist• Analysis during emergency• Analysis of repetitive failures• Analysis of critical problems• Analysis of simultaneous downtime• Analysis to achieve zero downtime• Paper Analysis• Analysis of Annual shutdown & overhaul

Failure Analysis Strategy

• Gather all available info & conduct interviews• Use failure analysis chart to know which part failed

• Gives frequency of problem, MTBF, cost• First step is to obtain all the relevant WO listed in file &

seek further explanations

• Determine the cause of Failure of a Part• Lack of PM, Faulty Design/repair, Operator error, etc

• Determine Corrective Actions to solve problems• When solution is too complex, time consuming, Zero

failure is mandatory and/or process modification needed• Then refer solution to maintenance engineering or research lab

System Level Failures

• Assembling of comp to build eqpt affects overall failure rate b/c of failure mode of each component• As a result, failures tend to be randomly distributed and

follow the exponential distribution

• MTTF also does not tell much about the distribution• HUMAN FAILURES (HF)

• Causes of HF can be categorized as Random, Systematic & Sporadic (most difficult to control)

• HF can be controlled by creating right env, Job enrichment, Trg, motivating.

Downtime• Effective maint program indicators include maint cost,

downtime, prod loss, safety etc• Downtime can cost money by idling production

workers, over and above the maint costs• Prod loss costs may be suffered if a deadline machine

causes a loss of sales

• Records should be kept of all downtime occurrences, & the downtime or prod loss costs should be charged to the responsible deptt• Tool deptt --- lack of tooling• Material deptt --- lack of materials

• Plot curves of downtime hrs/costs for better control & provide additional info for analysis of repetitive failure

Downtime and Prod Lost Costs

• Downtime does not always cause a prod loss when;• Redundant eqpt is available (if one fails, other takes over)• Eqpt is producing into in-process storage• There are product stockpiles in the external dist system• Plant is not operating 24 x 7 hrs per week• Downtime on prod eqpt is caused by other items like lack of tooling,

operators, raw materials, operator idle time etc

• Eqpt downtime can result into prod loss in the following order of severity;• An irretrievable loss in sales• Loss of Prod (recoverable through overtime)• Productivity loss suffered by some deptts• Maint productivity loss is suffered as a result of not using the downtime

improvement cycle

Downtime Improvement Cycle (DIC)• Step 1. Categorize eqpt by criticality & write PM

instructions in order of criticality• Step 2. Perform Preventive Maint tasks• Step 3. Record Breakdowns, sort by eqpt part that

failed, reason for failure, & corrective action taken• Step 4. Analyze highly repetitive failures• Step 5. Determine & Implement Corrective action

• Correct operational abuse, • Replace incorrectly selected eqpt• Correct reason for faulty repair• Review faulty PM instructions• Redesign Eqpt, Correct random/chance failures

Implementing Corrective Action

• Feedback systems together with maint analysis may result into backlog. Backlog of work should go through the following steps;• Step 1:- Study feedback data. Log significant problems,

assign priority No.• Step 2:- Study detailed data, determine initial part that

failed, determine cause, plan corrective action, assign priority for implementation, estimate cost & downtime req

• Step 3:- Assign new priority designation (which have a marginal ratio of benefits to cost), Either Reject, Refer for further analysis or Log in deferred improvement log

Repair Records• Record of eqpt maint tasks done on W.O form

• Considered most imp source of info to facilitate maint costs, failure analysis & writing PM instructions

• Provides a mean for screening & authorizing work• Provide cost data segregated in a logical manner• Provide feedback info on repetitive failure for analysis• Provide a tool to facilitate planning & sched of maint work• Facilitate control of productivity

• W.O form is used in 2 ways; Blanket & Special W.O• Blanket W.O are used for routine repetitive small jobs

when processing cost is more than the job• Normally written only once in a year, person merely charges the

W.O for the time he spent at the end of day thereby saving time & cost of filling out & processing a special W.O

Summary Reports

• Info for following summary reports is obtained from W.O form• Maint cost -- Rs/Ton, Rs /Unit produced• Annual eqpt maint report which summarizes W.O costs

for the year by eqpt number• Monthly Year-To-Date (YTD) Major Problems Reports

• Quick & easy means of surfacing principal maint problem areas

• Janitorial cost in Rs per ft2

• Costs of each work by type code, including percentage• Parts use report

Outages

• Facts about outages must be considered and handled to reduce cost of maintenance & prod loss• Handling of eqpt can be divided into 2 categories

• Emergency Outages; Decide how to fix? APPROACH for critical/ non-critical items, major/minor prod loss etc

• Preplanned Outages (in continual/intermittent usage);

– Decide how to reduce downtime while doing 100% BD maint, Light and Heavy Preventive Maint Plan

– Use CPM, special jigs/fixtures/material handling eqpt

– Provide detail repair instructions/drwgs to reduce time

Outages

• Products spillage, dust generation, litter & uncollected trash may also have unfavorable side effects not experienced in an ordinary eqpt malfunction like;• Low Morale, Prod Loss, Safety & Health hazards, Fire etc• Focus on ‘What happened?, Why did it happen?, What can

be done to prevent such occurrence?

Iatrogenic Failure

• Refers to breakdowns caused by a mechanic or electrician trying to cure/troubleshoot something else• ‘Experience’ is said to be the result of making mistakes

• Every time someone touches the piece of eqpt for any reason, there is a small but measurable risk 0f iatrogenic failure• 70% of the PM inspection part goes wasted but the

problem is that we do not know which is this 70%

• PM activity is desired only to that level which helps to achieve the set targets of safety, reliability of ops

Iatrogenic Failure (IF)

• IF can be reduced through measures like;• Reduce to min the number of time you touch the eqpt• PM persons should have the right work order, tools,

parts, supplies, eqpt, drwg & manuals before they start PM

• Be sure the eqpt is numbered, easily identifiable, complete inspection is documented

• Intelligent & robust designs can create multiple barriers for iatrogenic failures through various systems, ops procedures, processes

Optimize Maintenance Strategy

• Minimize downtime• Maximize output• Cost effective use of resources• Provide a quality product • Safe and env friendly operation

Do it well

Do the right maintenance

Maintenance Analysis• Production loss cost is included as the cost of

maintenance failure• In case where the old & new methods compare very

closely, the comparison should be done in writing• For In-determinant Maintenance;- determine action

by guesstimate• When PM cost curve & BD cost curve are added together,

the most economical maint point is achieved• Downtime hrs will stop diminishing when the oiling

frequencies go beyond points 1 & 2• The points 1 & 2 represent the two desired goals of PM

system which achieved seldom through Trial & Error

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