You
can wait ‘till it breaks, but what will it cost you in downtime?

A
maintenance engineer checks the condition of a motor and pump and enters data
into a PC-based PDA. Source:
SKF.

Outside
firms provide several types of maintenance support including engineering,
technical, assets and more. Source: Advanced Automation.
What
does it cost per hour when your bottling line goes down due to an unforeseen
failure? What does it cost to repair a 500 hp motor that didn’t need service at
all, but was overhauled incorrectly and failed four weeks later?
A savvy maintenance strategy begins with hard questions based in reality. What
does it cost when a part fails in your production line? How critical is it to
your business? Jim Oszewski, manager of maintenance engineering at SKF’s Asset
Management Services, tells a story about a bottling line that came to a
screeching halt. For many bottlers, an hour of downtime quickly runs into the
thousands of dollars. In this particular line, the cause of the problem had
nothing to do with the bottling equipment. Because the switchgear for the
system was located near the washing and bottling stations, moisture and sugar
built up and caused a power interruption. How critical was the switchgear
failure to the operation of the bottling line? This seems like a stupid
question, but in many cases Oszewski has seen food processors that have never
evaluated the cost associated with the failure of specific parts of the system.
What some people may think of as maintenance strategies, Oszewski prefers to
call tools (or tasks) used to build a successful maintenance strategy. These
tools include run to failure, preventive maintenance (PM), predictive maintenance
(PdM) and reliability centered monitoring (RCM). Choosing the tools to protect
against loss is the second step of an effective and savvy maintenance strategy,
assuming assessing criticalities, the first step, has already been done. In the
absence of an actual maintenance strategy, many producers simply run their
equipment to failure. This may work for a while, but could eventually put a
processor out of business.
Ted MacDonald, asset performance manager with Invensys Process Systems’ Avantis
Division, defines maintenance strategy as a holistic concept consisting of
tactical elements (PM, PdM and RCM), which addresses the effect of asset
availability and utilization on the needs of the business. PM, PdM and RCM all
have their place, but their effectiveness is rooted in the application of best
practices.
Taking maintenance seriously
“The
best way to maintain equipment is not to use it,” jokes Wonderware’s Claus
Abildgren, marketing program manager, production & performance management.
“It’s always a tradeoff between asset availability and asset utilization.” For
example, a processor may want to slow down a packaging line because it will
experience longer up time before maintenance is needed. It may run without a
stop for six months at the slower speed, but may fail outright in two months
when run at maximum speed.
Unfortunately many processors elect the run-to-failure mode for a maintenance
strategy because they never considered the criticality of a system component
failure. Kevin Hardig, SKF global strategic accounts manager, says some
processors actually evaluate the criticality of devices, and know that a major
failure could kill their business. Yet, they still choose not to implement any
maintenance strategies.
While ignorance may be bliss, some processors have other reasons for neglecting
maintenance programs. Bob Vogel,
Advanced Automation’s director of support services, says many processors put
maintenance on the back burner because of resource restraints. For example, a
key person or maintenance engineer in the plant leaves, and then everyone
scrambles to put out fires.
Similarly, Hardig adds that plant personnel are there to make a product, not to
repair machines. So when a problem occurs, and there is only one maintenance
person, it’s not likely that line personnel will want to repair equipment.
Another problem, says Hardig, is often a lack of properly trained personnel to
do the job. For example: a processor has a sophisticated condition monitoring
system, and an engineer writes a work order to repair a motor experiencing
vibration problems, but there are no experienced motor technicians who can
properly overhaul and lubricate the motor.
Vogel sees many processors that don’t even have a simple computer-based system
to track maintenance. And when they do buy a computerized maintenance
management system (CMMS), they don’t integrate it properly or train enough
people on it. All too often, there is only one person in the company that knows
how to use it.
Matt Kettunen, project engineering director at Cadbury Schweppes Americas
Beverages, suggests there are several good automated systems available, but
it’s not necessary to start out with an automated system. “I’m a very strong
proponent of having an organized system. It doesn’t matter if you have a
database you can query or a stack of paper. A stack of paper is way better than
nothing!”
Sometimes processors have maintenance programs in place, and through
acquisitions, wind up with several disconnected maintenance software
applications, or none at all in some locations. Such was the case with ACA
Co-operative Ltd. in Nova Scotia, which produces poultry
and eggs. According to Ryan House, IS manager, ACA now consists of two entities
that had separate maintenance software applications with repair parts totaling
more than 20,000 part numbers. The maintenance applications were also
disconnected from ACA’s other business programs. ACA implemented CSB-System
software to pull together the maintenance operations from all the facilities,
add maintenance functionality where it didn’t exist, and combine it with all
business applications to have one cohesive system. Maintenance operations were
added to the egg division, hatchery and barns. Maintenance items are now on the
balance sheet, and there has been a 20% reduction in company-wide inventory
levels.
According to Vlad Bacalu, product manager at Advanced Technology Services, a
food processing plant should create an equipment reliability strategy that
identifies the correct maintenance tasks performed on the right equipment at
the right time for the right reason. Once the criticality of the equipment has
been determined, the reliability analysis will identify applicable and
effective maintenance tasks to preserve the function of the equipment.
As stated earlier, a maintenance strategy consists of one or more tools or
tasks (run-to-failure, PM, PdM and RCM). It might seem as though run-to-failure
isn’t a tool or part of a maintenance strategy because it implies the failure
of a part may not be that important. And that is a correct implication. “If the
cost to the organization and the speed of repair is less than changing the part
before failure,” says Rudy Westervelt, president of Power in Learning, “then it
can be run to failure. You may run a small motor or a pump to failure, then
wire in a new one when it fails.” But he suggests processors have a better plan
for their refrigeration system, especially if replacement parts have long lead
times. Otherwise, a processor may want to plan a new business that doesn’t use
refrigeration.
PM: A place to start
Beyond
run-to-failure, Bacalu says tasks can be time directed (PM activities),
condition directed (based on findings from PdM tools) or failure finding
activities that can be conducted by maintenance personnel or equipment
operators. Therefore, a reliability strategy should include the correct use of
both PM and PdM activities. Performing PM alone does not provide the complete
benefits of a reliability strategy. Studies show that a large number (43%) of
PMs cannot be justified by a cost analysis. The same data shows that about 30%
of PMs can be eliminated by using predictive maintenance instead, but this
approach alone could lead to excessive maintenance costs by performing too much
predictive maintenance on the equipment. Bacalu says a reliability study should
optimize PMs and eliminate intrusive tasks by replacing them with
condition-based monitoring and predictive maintenance tools.
From an OEM point-of-view, Kelly Golden, lease supervisor at FMC FoodTech,
suggests food processors choose a PM-based strategy because it is fairly easy
to implement, simple to teach and cost effective. Most companies that sell
equipment provide guidelines for maintenance managers and technicians, making a
maintenance program easier to follow and a good first step for processors with
no existing maintenance strategy.
PM often works well in the food and beverage industry where multiple processing
lines are coupled with filling and packaging lines. According to MacDonald,
these lines generally run on an intermittent basis due to campaign production
and cleanout cycles mandated by regulation. The inherent periodic shutdowns
provide a natural opportunity for carrying out PM.
Though PM is usually better than nothing at all, there are two issues
associated with it. First, the “if it ain’t broke, don’t fix it” axiom may be
good advice. Second, equipment that actually needs attention may not get it
because maintenance time is spent on equipment that doesn’t need it. As in the example of the repair of the 500 hp
motor (which showed no signs of wear) at the beginning of this article,
maintenance done by the calendar may not be necessary. In this case, says Hardig,
technicians reinstalled the bearings incorrectly resulting in motor failure
four weeks later. This shut down the line for some time while the processor
scrambled to repair the motor. Brandon Henning, GE Fanuc Automation, food and
beverage industry leader, suggests teaching employees “flow to the work.”
“Often you will find employees doing PMs when another piece of equipment is
down. Make sure that you have a good flow-to-the-work system that both
encourages effective preventive programs and shows how to move to the
breakdowns as they occur.”
Henning also suggests processors develop a good equipment hierarchy for the
plant that allows understanding of the key components for each line as well as
sub-components. This hierarchy will help employees understand how each
component relies on the others on the line and allows plant management to do
cost roll-ups that show how outages and long repairs affect the profitability
of the plant at different levels.
PdM applications
According
to David Barberree, food industry account manager for Rockwell Automation, in
applications where downtime is unacceptable, product quality is at risk and
repair and replacement costs are high, a PdM approach should be applied. For
example, large grinding applications can cause huge amperage spikes in motors,
causing energy issues. When manufacturers change from one batch to another,
some products can cause motors to overheat. Food processors must make sure they
have the tools to understand the health of their equipment and identify the
potential downtime associated with that particular batch recipe. A predictive
approach lowers the total cost of ownership, maximizes efficiency and
bandwidth, and helps identify the root causes of maintenance and reliability
issues. Manufacturers may shy away from this approach, however, since it
requires upfront investment, commitment and additional knowledge and skills for
each application involved.
While PdM has been highly valued in the petroleum refining and power generation
industries where, according to MacDonald, failure in complex equipment could
lead to catastrophic failure, some food processors are adopting it in
applications where unplanned failure cannot be tolerated or afforded. A PdM
system relies upon various types of sensing devices (vibration, temperature,
IR, etc.), combined with appropriate asset performance management software.
This software can monitor critical equipment and, if the software has a rules
engine, can analyze the incoming data in various ways, interpret it and offer
preliminary actions so the maintenance staff can avert a major failure.
According to Matt Ruth, director of the food and beverage group at Advanced
Automation, vibration monitoring and PdM tools are used in about 1% of the food
industry. But it’s this 1% that is ahead of the curve. Ruth sees a lot of
run-time tracking, but there aren’t many processors taking advantage of
condition monitoring techniques such as monitoring the bearings in mixer
motors. For some manufacturers who are already using process control systems
such as Wonderware, conditioning monitoring tools may be available or already
in place, both real time and historical.
RCM strategies
According
to MacDonald, RCM has its roots in the airline industry. It involves
hypothetical analysis of failure modes and effects on critical equipment and
subsequently prescribing the most appropriate maintenance tactics to manage the
consequences of the failure. PM, PdM and run-to-failure tactics are often
defined from the RCM analysis.
According to Robb Dussault, manager Schneider Electric Services, RCM, while
representing a perfect balance between reactive, proactive, time-based and
condition-based maintenance, is a longer-term ideal to work toward, much like
Six Sigma quality standards. A realistic plan should include short- and
medium-term phases that consider available technology, current processes and
training at every staff level.
RCM may not be practical for every processor. Often, current best manufacturing
practices can be used to determine RCM’s applicability. For those still at a
run-to-failure mode, RCM may be overkill. Henning suggests the following steps.
Put a good PM schedule in place. Organize a maintenance “center of
excellence.”
Invest in an enterprise asset management (EAM) system.
Develop an automation strategy that will further expose maintenance,
efficiency and capacity issues hidden to the plant.
Utilize the automation strategy to move away from OEE and toward
process reliability.
Move to a RCM strategy that will have the metered and runtime
components of a predictive strategy, along with capacity analysis measures
needed to drive the plant forward while driving costs out.
Think differently
“A maintenance program should be viewed as a profit center-not a cost center,”
says Hardig. Processors don’t realize the impact on the bottom line until
equipment fails. Hardig describes one instance where a processor increased the
reliability of existing equipment through proper maintenance strategies and
obviated the need to build a new line.
“Maintenance is about costs,” says
Patrick Pilz, president/CEO of CSB System-International. “You do maintenance to
enhance your ability to execute customer orders. With a maintenance system, you
want to get a certain ‘equipment availability’ at the lowest cost possible.”
Pilz adds, “If you don’t have these numbers, a good start is putting systems in
that get you the numbers you need to make these decisions. The biggest savings
from maintenance systems [often] come where you would least expect them.”
For more information:
Kevin Hardig, SKF, 513-941-8254, kevin.g.hardig@skf.com
Ted MacDonald, Invensys/Avantis, 905-516-9560, ted.macdonald@ips.invensys.com
Claus Abildgren, Wonderware, 949-727-3200, claus.abildgren@wonderware.com
Jim Oszewski, SKF, 925-943-7077, jjoszewski@erineng.com
Bob Vogel, Advanced Automation, 610-458-8700, robert.vogel@advancedautomation.com
Vlad Bacalu, Advanced Technology Services, 309-693-5959,
vbacalu@advancedtech.com
Rudy Westervelt, Power in Learning, 909-563-8700, rudy@powerinlearning.com
Kelly Golden, FMC FoodTech, 678-797-4253, kelly.golden@fmcti.com
Brandon Henning, GE Fanuc, 434-978-6139, brandon.henning@ge.com
David Barberree, Rockwell Automation, 852-9036-0450, dabarberree@ra.rockwell.com
Matt Ruth, Advanced Automation, 610-458-8700 (ext. 274),
mruth@advancedautomation.com
Robb Dussault, Schneider Electric Services, 978-975-9679, obb.dussault@us.schnieder-electric.com
Patrick Pilz, CSB-System Intl., 619-640-0436 (ext. 203), obb.dussault@us.schnieder-electric.com
Sidebar 1: How to create a maintenance strategy
1.
Understand the characteristics of your plant operations. This is important
because it will affect maintenance resource use, windows of opportunity,
preventive maintenance (PM)/predictive maintenance (PdM) schedules and the
amount of maintenance required.
2. Establish a maintenance plan for each process and packaging line. This
should include appropriate preventive maintenance routines as well as elements
of non-destructive testing where appropriate.
3. Establish a maintenance schedule for the plant, balancing the production and
maintenance needs to use available windows of opportunity first, and then look
at the best way to use specifically created maintenance windows.
4. Establish the initial policy for spare parts and the overhaul and/or rebuild
of production equipment.
5. Establish best practice processes and procedures for conducting maintenance,
including the necessary technology to facilitate these, such as a computerized
maintenance management system (CMMS) or an enterprise asset management (EAM)
solution.
Source: Invensys Process Systems.