A Day in the Life of a Proactive PdM Technician

By Ricky Smith and Carey Repasz

What value does a PdM Technician provide to a Proactive Organization? The ability to identify a defect or unacceptable condition that will lead to

equipment failure and unexpected downtime. The purpose of early defect identification is that work can be planned, scheduled, and executed without getting close to a failure on critical assets.

We are using the PF Curve to demonstrate this message.

PdM Technologies VS PM (How much risk are you willing to take?)

Copyright 2011, GPAllied

The ability for maintenance work to be scheduled in the windows of opportunity operations/productions offers us the chance to run as much production as possible without an upset. We want production to produce as much quality product as possible with minimal interference from maintenance. What value a PdM Technician cannot provide a Proactive Organization?

“Estimate of when the failure will occur”. The focus is on detection of defects that are random in nature. To attempt to trend the propagation of a defect and forecast the actual time of functional failure is a difficult proposition as well as a very poor use of the technician’s time. The defect will never be cheaper to address and our work execution processes must be utilized to address the timing of repairs, not the PdM team. I have seen

this one issue that causes more pain to an organization than any other and management wanted to know “how much longer will it run”. My answer always is “how much risk are you willing to accept”. After a while people lose confidence in PdM Technologies.

“Predictive Maintenance is not a true term”. On Condition Monitoring is the true definition of PdM because we are measuring the condition of specific failure modes are a specified time and it may be 30-90 days because a reading is taken again.

“If you really want to know what is the most effective method for addressing failure modes we may want to begin by determining what the most dominant failure pattern in your organization”. Less than 2% of organization can identify this failure pattern statistically because they do not have the data from their maintenance software to support such a decision. If you look below it shows that during the Nowlan and Heape study of the 1960s they found most failures were random.

Failure Patterns from Nowlan and Heap Study, 1960s

You could identify your dominant failure patterns for your equipment if your failure data were available and accurate. I am sorry we are all out of crystal balls.

Where does proactive work come from? Here is how this PM and PdM Work breaks out; PM Execution: 15% of Work Results from PM: 15% of Work Condition Monitoring Execution: 15% of Work Results from Condition Monitoring: 35% of Work (planned and scheduled work, Emergencies not included

“PdM’s focus is on the future not today’s problems”

A Potential Failure (Low Defect Severity- time to plan and schedule proactive work) is an identifiable physical condition which indicates a functional failure is imminent and is usually identified by a Maintenance Technician using

Predictive Maintenance or Quantitative Preventive Maintenance.

Copyright 2011, GPAllied

At the beginnings of the maintenance day shift: The day begins with the PdM tech reviewing any equipment which has been repaired or replaced in the past 24 hours. If any equipment has been changed or repaired the PdM Tech who handles can identify specific failure modes for the work completed will conduct follow up inspections of repairs for the purpose of QA/QC that the defect has indeed been removed and that no new defects have been introduced as a result of maintenance activity. If a defect is identified, a new work request is written by the PdM Technician to make the repair. On the work request will be the cause of the potential failure. This happens many times because of “human induced failures” either with your current maintenance technicians not having effective procedures with specifications or your rebuild vendor now having any or following them. This inspection is critical to continuous improvement of maintenance processes and establishing buy in of PdM. The correct method for repair or replacement of anything on a critical or important asset would be for a PdM Technician to conduct a baseline and tell management if the equipment is defect free or not after the work. This goes for next installations as well. Planned and Scheduled Work: The PdM Technician has a planned and scheduled route to conduct his/her inspections and to conduct baseline readings on repaired or replaced equipment during the day. This is a busy job if done correctly. Here is how their schedule may look for one day.

Key Learning Point: If your maintenance process is reactive then your PdM Technicians will be reacting to the urgent and emergency work so their true value is diminished. “You know you are in Reactive Maintenance using PdM when…”

…management asks a PdM technician the question “how long a piece of equipment last before it fails”? So a PdM Technician may get it right 40% (I doubt it) of the time, what if we could get it right 98% of the time? Sorry all PdM Crystal Balls are sold out.

…a company only uses Vibration Analysis and Infrared Technologies. So a technician can only identify potential failures on specific failure modes addressed by the two technologies. What about the failure modes which can only be address by ultrasound, UT, MCA, etc?

…company makes a repair after a defect (ex: loose electrical connection) however no Infrared Technician insures the defect has been identified after the electrical defect has been identified. Such as these loose electrical connections below.

Outage Complete but has the Defect Been Eliminated?

Copyright 2011, GPAllied

…Ultrasound is the only used for compressed air leaks. …PdM Technicians do not even know each other and never work

together. … a company’s PdM program is not focused on specific failure modes so

they conduct “too much PM”. … no one uses infrared technology for low voltage applications, only high

voltage. See pictures below.

Copyright 2011, GPAllied

…an electrical technician refuses to use a torque wrench on a loose electrical connection found through infrared inspection. How long will it take for the connection to burn up or become loose again? See example below.

Allen Bradley Breaker Torque Manual

…if your maintenance technicians do not use repeatable effective work

procedures. Expect a lot of findings by the PdM Group. …if your main source of Failure Mode identification is when something

fails you may be in reactive maintenance.

Proactive PdM Daily Schedule Example

Work Order Number/Schedule

Scheduled Work

Conduct Baseline

Take Readings

Write Work Request

0630 XXX-111 Pre-shift Validation

Overnight Repairs No Defect Detected Not Required

0700: XYZ-123a PdM Route No Defect Detected Not Required 0730: XYZ-123b PdM Route Defect Detected Yes 08:30: XTZ-123c PdM Route No Defect Detected Not Required 0900: Emergency

WO AC Induction

Motor Replaced Defect Detected – Vendor called

Use Maint Techs WO Number for Emergency

13:00 XYZ-123d PdM Route Defect Detected Yes 14:00 Urgent WO New Gearbox

Installed by construction

No Defect Detected Baseline taken Oil Analysis sent out

Yes for Oil Analysis

15:00 – Work Closeout

End of Shift

Available for EM Callout if required

Early Morning for the Planner: Field inspections – Armed with an the results from PdM, PM, and Work Request, Job Inspection forms, and a digital camera, the planner will begin making his/her inspection of all of the job sites. The planner has established a logical route to minimize travel time and will make notes of the specific needs of the request, any ancillary work that should be completed by the mechanic while at the job site, and all of the other applicable information required for a well planned job. The planner will make note of the complexity and predictability of the various issues relative to the particular job in order to create a job plan most effective yet suited to the particular job. Also, the planner will pay particular attention to job issues where significant delays were identified in the Wrench Time study. Understanding and watching for complexity, predictability, and likely wrench time losses will enhance the likelihood of creating a job plan that will minimize delays during execution and result in a high performing work force. More on these topics can be found in the 3rd edition of “Planning and Scheduling Made Simple”, Smith and Wilson. Immediately after completing field inspections is a good time to start ordering parts, or at least creating a list of parts to order, depending on the time available before meeting with the supervisor, scheduler, and maintenance coordinator.

Planning and Scheduling Using PdM

Copyright 2011, GPAllied

In particular, identifying the parts that will require more than 24 hours to obtain will be important. These parts should be ordered today and the status should be changed to “Waiting At this point in the process, it is not known when the job will actually be scheduled so, any parts not on site should be ordered on the same day they are identified as a need. Parts that are available from the storeroom should be put on reserve so that they will be available for ordering the day before

the job is scheduled for execution. The planner will also need to review the status of parts previously ordered and update the status to “Ready to Schedule” on the work request where all parts have arrived and storeroom parts are all on reserve. Some organizations go ahead and have storeroom parts delivered and placed in Parts Kit boxes for each job. This process can work fine however, one draw back is when jobs get pushed to the future for execution, you can end up with a lot of Parts Kits to keep track of or, you can end up sending some stuff back to the store room if jobs get canceled for what ever reason. If you have a firm parts reservation system, it will be the best of both worlds where the parts can’t be bought out for a different job, yet if the job gets cancelled it doesn’t have to be returned. Less handling and better inventory accuracy provided by the reservation approach will reduce cost From a PdM Technician’s standpoint his/her time needs to be scheduled to validate a defect which has been eliminated and establish a baseline anytime a repair is made. If you do not conduct this expect unexpected failures will occur and makes people believe PdM is not effective.

It may be a great idea to use your PdM Technician to assist with the identification of causes of equipment failures as well. They can assist in Root Cause Analysis, repeatable equipment or process issues, etc. If you have questions or would like a one hour private WebEx for your company on the subject send an email to Ricky Smith, rsmith@gpallied.com or Carey Repasz, crepasz@gpallied.com. A failure Mode Driven Strategy is what every company needs.