Corrective Maintenance Task Generation
Robert Apelgren,
Senior Reliability Engineer
Posted 9-27-04
Maintenance cost
or maintenance loss? Maintenance in today’s plant is
a dynamic function of the ability to adapt to quick changes and to new policies
and management techniques. An inherent problem common to many maintenance programs
is that manpower is one of the first things considered when cost reduction
is sought. The loss of manpower poses continuous challenges to any maintenance
manager who is striving for world class status. Corrective maintenance experience
is one of the critical areas of expertise that is often lost.
Plants are changing and expanding at an ever-increasing pace to keep up with
the competitive environment in today’s society. The equipment being produced
has become more efficient and reliable to meet the growing demand for productivity.
With this increase in efficiency and reliability, a lot of plant equipment
is now more complex in the mechanical, electrical, hydraulic, and pneumatic
systems. The days of “backyard mechanics” in plants are coming
to an end. A majority of plants now require a degree or specialized certification
as qualifications for employment.
There are many programs that recommend corrective maintenance task development
as an improvement to a maintenance program. Reliability Centered Maintenance
(RCM) and Business Process Reengineering (BPR) are programs designed to move
maintenance and management programs to the next level. Such programs consider
processes and provide recommendations for change to improve the reliability
and productivity of equipment and processes. Programs of this nature can be
a great investment and should be researched thoroughly before undertaking the
long-term change that can be involved after an analysis is complete. Although
the programs can reap large rewards in short and long term benefits, implementation
and follow through are the keys to truly effective programs. This includes
implementing the results, periodic update analyses, and progress reports. Commitment
to continuous improvement is paramount to the success of such programs.
RCM is a process that is conducted to improve maintenance programs. The focus
of RCM is function preservation through the most cost effective, safest, and
technically feasible methods. RCM can improve a company’s maintenance
system and help increase the overall productivity of most processes. If a company
is planning on having an RCM analysis conducted a good corrective maintenance
program can reduce RCM analysis time and improve the results of the analysis.
If a company has not already implemented an effective corrective maintenance
program, it will generally become a recommendation of an RCM analysis to implement
one.
BPR is similar to RCM, but on a different scale. RCM is historically
focused on maintenance. BPR as an expansion of RCM principles,
focused on change in any area of a company with any function.
BPR is an effective tool at finding improvable areas in a management
system. Manpower reduction may be an effect of a BPR process,
when cost effective. Note that manpower reduction, especially
in the maintenance department, is not always the best answer
for cost reductions.
Cost reduction is something that managers must continuously
consider. The quickest routes to cost reduction are not always
the wisest choices. The popular place to go for quick cost
reduction is manpower. Companies stress that employees are
their greatest asset. Yet, when it comes time for reductions,
employees are one of the first assets to be reduced.
Manpower experience embodies tribal knowledge within a company.
When an employee is released, a certain amount of tribal knowledge
is lost. After releasing personnel, some companies find themselves
short handed and have to hire new employees. Training time
and costs can be higher than the cost of maintaining the personnel
that were released.
Corporate knowledge of experienced employees is a valuable asset to a company.
By effectively capturing and maintaining that corporate knowledge, the impact
of personnel losses is reduced. This is not a new concept to experienced managers
who know the trials of maintaining an experienced workforce. The reduction
of man hours in maintenance tasks does not mean that the next logical step
is to reduce the number of employees. Another option for those managers who
want to prepare for the future is to implement a “Continuous Improvement” billet.
This alternative option for cost reduction is “Corrective Maintenance
Task Generation”.
Corrective Maintenance Task Generation is best performed by the same personnel
who perform corrective maintenance. The normal technician’s time schedule
does not allow the time to document tasks in detail. Some companies rely on
the maintenance supervisor to document and implement new preventative and corrective
maintenance tasks. Maintenance supervisors are often too heavily tasked to
make this option feasible without risking lost productivity. In addition, maintenance
supervisors do not perform corrective maintenance tasks on a regular basis.
Therefore, the process of remembering how to perform the task can take longer
and be incomplete. Detail is the key to effective corrective maintenance tasks.
One solution to the manpower issue is to maintain an extra technician for documenting
corrective maintenance tasks. Technicians can be rotated on a periodic basis
by area of expertise to document corrective maintenance tasks, perform parts
research, and perform lock-out/tag-out verification for those tasks. Corrective
maintenance tasks can then be input into the Computerized Maintenance Management
System (CMMS) or a database kept by the maintenance manager for future use.
Whenever a corrective maintenance task needs to be performed, the technician
can print a copy of the work instruction detailing the procedure for locking
out equipment, parts needed, and how to perform the task. This kind of corporate
knowledge cannot be easily passed person to person by word of mouth.
The benefits to the corrective maintenance task generation can be seen in many
areas. The first benefit is that the time for completion of common corrective
maintenance tasks can be reduced by a conservative estimate of 10%. For example,
a task that takes 30 minutes on a normal basis can be reduced by 3 minutes.
For a production line that loses $60 for every minute it is down, this can
save $180. The task generation will take about 3 hours at an estimated rate
of $90 ($20 for salary and $10 for benefits per hour). If the casualty happens
5 times per year on average, the cost of lost operation alone would be $9,000
($60 per minute times 30 minutes times 5 incidents). With the detailed maintenance
task it would be $8,100 ($60 per minute times 27 minutes times 5 incidents).
The savings in the first year would be $810 ($900 savings minus $90 for the
task generation). Over the long term, the cost savings would more than pay
for the extra technician. Alone, this task may seem like a small savings, but
combined with other tasks the savings can soar. An example of the corrective
maintenance task is described in Table 1 with no written task compared to a
written task on the replacement of a hydraulic cylinder that is leaking. The
following comparison assumes that the system will restart properly after the
lockout is cleared. With no written procedures, the system is less likely to
restart properly.
Written corrective maintenance task No written corrective
maintenance task
1. Print out corrective task. (3 min) 1. Lock-out system. (5
min)
2. Lock-out system. (4 min) 2. Find part number and retrieve
part. (7 min)
3. Retrieve part. (3 min) 3. Replace cylinder. (15 min.)
4. Replace cylinder. (13 min) 4. Clear locks and restart system.
(3 min)
5. Clear locks, restart system, and sign off corrective maintenance
task. (4 min)
Total time: 27 minutes Total time: 30 minutes
Table 1. Corrective maintenance task.
The knowledge a technician gains while performing the task
writing process will help prepare them for future positions
in supervisory or planning capacities. Technicians normally
spend very little time honing their administrative skills in
preparation to become supervisors. Too many technicians become
supervisors that are not educated on the “behind the
scenes” skills and concentrate on shop floor direction
instead of growing their personnel. The better trained a technician
is, the easier it becomes to supervise and manage them.
It is generally accepted that a plant is a very stressful environment,
especially when the onus is on to get the plant running again.
Technicians can get a small break from the reactive nature
of the job. The morale benefits of the “down time” can
improve overall work atmosphere and in turn the productivity
of the personnel.
The safety of performing tasks can be increased by having lock-out
lists and safety warnings with every task. When the pressure
is on to get equipment running, mistakes are more likely to
happen. The possible reduction of safety hazards can alone
be a large cost savings.
The level of detail of the corrective maintenance tasks can
be written to the realignment of the equipment after the task.
This will increase the probability that when the system is
started back up the system will perform to specifications.
The final and probably most important benefit for the maintenance
manager is the building of a corporate expert system. The building
of an experienced and well-trained workforce is expensive.
Corporate expert systems can build experience more quickly
in new technicians than can the “school of hard knocks.” Such
learning from mistakes can be costly.
Corrective maintenance task generation can produce long-term cost reduction,
especially when used to implement the results of an RCM or BPR analysis. The
process can help move a maintenance department to the next level and better
prepare for the future. Corrective maintenance task documentation can be used
in any system in conjunction with any other continuous improvement plan. Most
companies can perform this process improvement plan in some fashion, even if
only on a periodic basis. In doing so, they will reap the benefits of years
of tribal knowledge.
Robert Apelgren is a Senior Reliability Engineer. He received
his BS in Industrial Technology from Roger Williams University
and an MBA from the University of Phoenix. He is a Certified
Maintenance and Reliability Professional. He has 12 years of
maintenance experience as a technician, supervisor, coordinator,
consultant, and trainer.
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