Have you ever wondered what decision-making process drove previous maintenance administrations to set up your site’s asset-management program in the way that it currently runs? Program architects, in all realms of business, are notorious for poorly documenting the reasons and circumstances that lead to their decisions surrounding software selection, program set-up architecture, and business process. Often, a plant’s existing maintenance program is a result of legacy choices based on financial, political, and knowledge compromise, with many programs no longer relevant or equipped to adequately manage the current state of maintenance and asset demands.
A major casualty of a compromised legacy asset management system is the preventive maintenance (PM) program in which many of the PM job tasks are rudimentary, subjectively written in vague language, and globally assigned across many different assets. This scenario is typical when PM job tasks originally written on paper systems were transferred to a computer maintenance management software system (CMMS) many years ago. Those unsophisticated, often one- or two-line PM tasks, were in many cases purposely written this way to favour the initial CMMS software PM task field restriction on the number of allowable characters. Unfortunately, many of these simple PM job tasks, along with their simple scheduling rules, have continued to be ported across many CMMS software updates and platform changes with little or no modification. That type of process renders the information highly inadequate for a modern reliability-driven maintenance approach. It’s also not uncommon to use several PM job task styles and levels of sophistication with in a single system traceable to the addition of a new process, production line, or building that might be added into the database over a longer time frame by different individuals. If this scenario is indicative of your PM database, be assured your PM system is in need of an overhaul.
In a reliability driven maintenance approach, preventive maintenance is tailored to the needs of the individual asset, based on its design capability and “in situ” working conditions. Each asset is individually evaluated to develop a portfolio of Asset Reliability Profiles (ARP) from which relevant PM job tasks and schedules are developed. These profiles can be built off line in a separate database, or depending on the CMMS capability and configurability, may be included within the CMMS section often referred to as “Nameplate Data”. Developing a usable ARP portfolio commences with a listing of all assets prioritized by their failure risk to the organization. Each asset is then scrutinized to understanding its past failures, design capability, current/future demand requirements, design capability, and all reviewed alongside associated PM job tasks currently scheduled against the asset.
FAILURE RISK
Risk can be assessed in many ways, using numerous available matrices. However, a simple, three-level risk assessment is all that’s needed to commence the ARP and PM development process.
♦ Risk Level 1: Asset failure will endanger life or the environment
♦ Risk Level 2: Asset failure will jeopardize the production process
♦ Risk Level 3: Asset Failure has low impact and can be placed in a “Planned Run to Fail” category
Commencing with Level-1 assets, each asset’s history can now be reviewed.
PAST HISTORY
To understand the future is to first understand the mistakes of our past. This requires a data-mining expedition that examines how each asset has failed in the past, how often it failed in that manner, and, if the PM task was, or is, adequately designed to prevent failure occurrence.
To gain access to this information, it is crucial to confer with the asset-history caretaker(s), the first point of call being the maintenance planner. The next most resourceful information caretaker is likely to be an operator or maintainer who has worked with, and parented the machine for many years, from whom we can elicit insightful information about the equipment’s behavior under all conditions of use and abuse using a “3W” questioning approach.
“What” questions about standout failure incidents in the past, and in “what” context or circumstances they occurred. “When” refers to the time frames and repetitiveness of such occurrences. “Why” seeks to determine if any relevant root cause for the failure was, or can be determined. The same “3 W” questions are then used to data-mine the work-order history archives, including in filed-away paper documents, as well as the CMMS database whose electronic report will illuminate the quality, or lack of quality, of the current maintenance software set-up, program set-up, and PM job task/schedule.
DESIGN CAPABILITY
Assets are designed to operate within a set of recommended operating limits, for example, machines are rated by speed, size, temperature, etc. These limits, often referred to as operating specifications, are set by the manufacturer’s design engineer and are used to set safety limits and warranty thresholds. If a user regularly operates a machine or building outside of these limits, they not only void the warranty but also accelerate premature failure that is often not preventable through the PM program. Understanding these limits helps determine if any past failure was maintenance or operation related based on how the machine was operated at the time.
CURRENT/FUTURE DEMAND
Understanding current and future asset use/demand and measuring against its design capability allows maintenance to advise operations of its ability to prevent failure and maintain the asset based on the asset’s current specification or design. This information is used to determine how a machine redesign or upgrade can be best approached, or make a change to a Planned Run To Fail strategy knowing which spare parts are to be inventoried on site, and what the change-out and downtime implications will be to the operation should the demand change.
Documenting these four elements for each asset focuses all of the current available reliability information that can now be used to: 1) rewrite the most accurate and appropriate PM job task and schedule for each asset based on a replicable rule set; 2) set up criteria for reliability-reporting and search-capability requirements for updating the CMMS set-up; 3) provide continual monitoring and validation of the PM system; and 4) deliver a chronicled PM-change history for all future maintainers and asset caretakers. The PM Job tasks are now ready to be built in a standardized interactive checklist format, suitable for use on paper or mobile electronic tablet to ensure maximum consistency in Om completion.
COMING UP
Stay tuned for a discussion of the PM checklist format in a later planning and scheduling feature for The RAM Review.TRR
ABOUT THE AUTHOR
Ken Bannister has 40+ years of experience in the RAM industry. For the past 30, he’s been a Managing Partner and Principal Asset Management Consultant with Engtech industries Inc., where he has specialized in helping clients implement best-practice asset-management programs worldwide. A founding member and past director of the Plant Engineering and Maintenance Association of Canada, he is the author of several books, including three on lubrication, one on predictive maintenance, and one on energy reduction strategies, and is currently writing one on planning and scheduling. Contact him directly at 519-469-9173 or [email protected].
