Maintenance Strategies

Dr David BagleeFaculty of Applied Sciences

ATF 205

Background

►Maintenance strategy is becoming a more important issue

► Today machines are integrated► Very little inventory stock held► Automation of processes increasing►Downsizing of workforce

Hidden Losses

Labour

BreakdownsPlant Trips

OperabilityReducedThroughput

Restart Losses

Poor QualityPoor Integrity

Low Morale

Visible Costs

Hidden Losses

Materials

Maintenance Strategies

► Reactive Maintenance (1)► Preventive Maintenance (2)► Conditional Maintenance► Predictive Maintenance (3)► Total Productive Maintenance (TPM)► Reliability Centred Maintenance (RCM)

Reliability DomainsR

ELI

AB

ILIT

Y

%

MAINTENANCE EXPENSE

Reactive Maintenance

Planned Maintenance

Predictive Maintenance

Reliability Centered Maintenance

Total Productive Maintenance

Reactive Maintenance

► Allow machinery to run to failure► Traditionally the exclusive maintenance

mode until fairly recently► Continues to be the predominate

method of maintenance►Many major industrial companies still

operate in this mode► Repair or corrective action is taken after

the fault has occurred

Advantages Disadvantages► Low direct costs► Less staff required► Appropriate for certain

applications

► High costs due to unplanned downtime of equipment

► Increased labor costs, especially if overtime is needed

► Costs involved with repair or replacement of equipment

► Possible secondary equipment or process damage from equipment failure

► Inefficient use of staff resources

► Does not support the true definition of maintenance

Preventive Maintenance

► Actions that detect, prevent, or mitigate degradation of a component or system

► Aims to sustain or extend useful life by controlling degradation to an acceptable level.

► Actions performed periodically prior to functional failures to achieve desired safety or reliability levels.

Preventive Maintenance

► A step forward from reacting to breakdowns to preventing breakdowns: Pioneered by the U.S. Navy. Analogous to an automobile schedule of

maintenance. Time intervals based on manufacturer

recommendations and machinery history experience.

Preventive Maintenance

► Scheduled maintenance activities are based on specific time intervals

Calendar days Run time Parts produced

► Includes routine tasks such as: Changing oil Replacing filters Greasing bearings Instrument calibration

Preventive Maintenance

► Includes measurement of degradation prone areas for rapid changes in out-of-tolerance conditions. Wear rings Alignment Shaft end play

► Useful against age related modes of failure: Wear Fatigue Corrosion

Advantages Disadvantages► Cost effective in many

capital intensive or potentially high impact processes.

► Flexibility allows for the adjustment of maintenance periodicity.

► Increased component life-cycle.

► Energy savings.► Reduced equipment

or process failures.

► Catastrophic failures still likely to occur.

► Labor intensive.► Performance of

unneeded maintenance.

► Incidental damage to components through poor maintenance practices.

Conditional Maintenance

► Maintenance actions conducted as result of a specific condition, or as a result of specific circumstances or events. Examples of Conditional Inspections

Aircraft hard landing Unscheduled disassembly Power Interruption Over/Under Voltage Lightning strike Over stress Unscheduled or scheduled shut-down

Predictive Maintenance

► Measurements that detect the onset of a degradation mechanism thereby allowing causal stressors to be eliminated or controlled prior to any significant deterioration in the component physical state.

► Results indicate current and future functional capability.

► Involves use of specialised equipment to monitor the condition of machines (Vibration, Oil Analysis, Thermography, Acoustic Emission, etc)

Predictive Maintenance

► Schedule maintenance activities when mechanical or operational conditions warrant to repair or replace deteriorated equipment before obvious problems occur.

► Allows assessment of whether equipment will fail during some future period

►Hence indicates best time to perform repairs or maintenance

Advantages Disadvantages► Increased component

operational life/availability► Allows for pre-emptive

corrective actions► Reduced equipment or

process downtime► Decreased costs for parts

and labor► Better product quality► Improved worker and

environmental safety► Improved worker morale► Energy savings

► Increased investment in diagnostic equipment

► Increased investment in training of staff

► Savings potentials not readily seen by management

Total Productive Maintenance► JIT based approach► Workers perform preventive maintenance on the

machines they operate► Skilled maintenance personnel train the operators

and develop ‘one-point lessons’.► Maintenance department moves from a ‘fire-

fighting’ mode to a prevention mode & re-engineering

► Restore deteriorated equipment through Improvement-Related Maintenance.

► Identify design weaknesses and improve equipment► Preventive (equipment manufacturers/operators

data)► Predictive (data analysis and periodic diagnostic

tests)

Reliability Centered Maintenance► Process used to determine maintenance

requirements of any physical asset in its operating context.

► Plan is based upon reliability criteria with priority given to the most critical components.

► Determine what types of failures are likely to occur.

► Focuses on preventing failures whose consequences are likely to be serious.

► Emphasizes the use of predictive maintenance practices.

► Utilizes previous aspects of reactive and preventive maintenance concepts, in concert with root cause analysis.

Strategy Development► Advantages

Towards more efficient maintenance programmes.

Eliminating unnecessary maintenance or overhauls.

Minimize frequency of overhauls.

Reduced chance of sudden equipment failure.

Focuses maintenance activities on critical components.

Increased component reliability.

Root causes of problems identified.

► Disadvantages Can have significant

startup cost Training Equipment etc.

Savings potential not readily seen by management.

Changes take time to implement

Service Organizations

► Maintenance issues are not limited to manufacturing

► Transportation firms (airlines, railways, haulage, dispatch companies, etc) must maintain vehicles in good operating condition

► Highways Department must maintain roads► Office personnel are reliant on computers,

printers, copiers and fax machines working properly

► As services become increasingly automated, service firms face more and more maintenance issues

Computerised Maintenance Management Systems

What is a CMMS?

► Computerized Maintenance Management System

► Very important operational and management tool

► Management of assets, improving reliability, reducing downtime.

► CMMS functions: automating administrative tasks gathering relevant information develop and manage a maintenance strategy plan schedules for maintenance, replacements,

upgrades.

Why use a CMMS?► The primary purpose of a CMMS is to manage, capture, and

track inspection, maintenance and repair activities of an organization.

► Basic CMMS functionality providing work orders to cover repairs and maintenance of

buildings, plant and equipment. They provide a scheduling facility for maintenance for planned

preventive work on maintainable assets. And they also generally collect costing details for the labor and

materials related to the work performed.► Advanced CMMS functionality

analyse maintenance and repair processes visualise trends eliminate manual data entry incorporate alerts, triggers, and escalation procedures shift focus from administrative tasks to maintenance activities. assist in planning and predicting future needs, prolong asset life,

manage processes.

Requirement for CMMS► Regularly scheduled equipment inspection and

maintenance prevents sudden and unexpected equipment failure and reduces overall costs

► The management of these programs, in particular reporting their current status and future needs, requires a CMMS. Managing the operation of on-site maintenance staff and contractors is a daunting and difficult task, however, if there is a corresponding record within the CMMS then this tracking and management is much easier.

► Even if you are duplicating data to what is in your contractor’s CMMS (the contractor’s CMMS may not be on your premises), it is extremely important that you have your own copy of data. Your contractor may cease to exist and for the sake of future reference and reporting it is essential you have your own CMMS populated with your own data.

CMMS Information► Consideration what information is stored – what do we WANT to

keep, and what do we HAVE to keep?► manufacturer’s specifications► management requirements► , there are many statutory requirements and regulations that

impact on this question such as fire, health and safety, and environmental legislation.

► Statutory requirements (programs) could be entered into a CMMS as a scheduled maintenance plan with labor, materials and costs for projecting estimated future costs. By keeping a corresponding record in the CMMS and using the job number as a cross reference to the paper record, the organization is able to quickly report on the status of the statutory work in preparation to annual signoffs and/or audits.

► Those of you who have had work place safety audits are aware that the first question asked is ‘Where are the maintenance records?’ A maintenance plan that includes estimated costs can be compared with the actual costs to ensure the effectiveness in the cost of asset preservation.

Selection of a CMMS► There are hundred of CMMS software packages on the market.► A major problem is to select the most suitable package for the organisation.

Look within your own organization and determine what is happening with the maintenance and inspection functions. Check if there is an existing maintenance program in place, check its functions and who manages the information gathering process.

Determine what maintenance is required to be performed on the assets. Prepare some sort of brief as to the facility’s minimum and optimum requirements for a

CMMS, the resources to manage the database and time frame for implementation. Research between 3 and 5 providers. Have them present their product to assess the

package in terms of ease of use, functionality and ability to meet your requirements. Evaluate each proposal for specific CMMS functionalities: Does it address your specific requirements? Does it minimize unnecessary or duplicate data entry? Can you automate administrative tasks, reminders and notifications of upcoming events? Can you incorporate inspections, and other activities in your CMMS? Can you manage and track inventories? Web accessible? PDA version What is its ROI?

► This is a simplistic approach to the selection process, however, it will give most managers a good starting guide to the selection of a CMMS.

Benefits of using CMMS

► Guarantee that all required tasks and activities are completed on time.► Incorporate various mechanisms to ensure execution of tasks, including automatic

listing of activities, reminders, alerts, escalation procedures, and easy access to information.

► Improve reporting and analysis capabilities.► Comply with Health and Safety Regulations.► Improve Business Planning and make informed decisions.► Improve operational efficiencies.► Increase productivity and profitability.► Perform activities effectively; simplify repeatable tasks; provide your staff with easy

to use tools that focus on performing tasks.► Let your staff spend more time performing service activities and less time on

paperwork and data entry.► Improve strategic and business planning; Analyze records, needs and patterns.► Identify trends and highlight potential problem areas.► Improve controls and accountability; Lead to better quality of work.► Ensure that service is performed according to warranties, guidelines and regulations.► Receive customized reports delivered to your email.► There are many additional benefits of using a system using handheld devices, in

comparison with manual or paper-based processes: minimizing errors, increasing accountability, and having the ability to quickly turn data into useful information. Last, solutions must be cost effective and providers must be able to demonstrate their business case and ROI (Return-On-Investment).

Need for a CMMS► Requirements depend upon the size of the organization,

type of assets, number and quality of staff available.► Should data be kept on computer - can it all be done on

paper?► Often preparation of reports for management is difficult and

time consuming because the raw data is not readily available

► Well-designed and easy-to-use CMMS solution can improve daily activities as well as index and sort through years of information related to the maintenance, cleaning and strategic planning of buildings, plant and equipment.

► Regardless of the size of an organization a database of the work performed must be maintained.

► Automation includes improvement of daily activities, automatic tracking of inventories, better work assignments, and shift of your focus towards exceptions, not routine matters.

Further Work

► Read the article Shibi, E. (2005) Common-Sense CMMS:

Combining Software and Handhelds. Maintenance Technology, Vol. 18, No. 1, pp 47-49.

www.cmmscity.com/articles/common_sense_cmms.htm