CHAPTER 1

CHAPTER 1

MAINTENANCE

“Act of causing to continue ” [New Oxford Dictionary]

TRADITIONAL DEFINITION :• “The combination of all technical and associated actions intended to

retain an item in, or, restore it to a state in which it can perform its required function”.

CURRENT DEFINITION :• “All actions that are carried out to safeguard the technical

integrity of an asset and to ensure its availability such that maximum cash returns can be realized from the asset thereby enhancing the value of the asset”.

• Preserve and prolong the working life of plant and equipment.• Upkeep and protection of plant, buildings, machinery and other fixed assets.• Safeguard investment by minimising deterioration.• Keep the assets in efficient working condition.• Ensure reliability of plant and equipment.• Minimise idle time and loss of production.• Maximise efficiency through optimum use of facilities.• Generate a safe and healthy, working environment and maintain safety consciousness.• Minimise maintenance cost.• Improve performance of plant and machinery.• Keep abreast of latest maintenance techniques and achieve excellence to

meet the new challenges.

ROLE OF MAINTENANCE

• To keep assets in top condition.• To avoid failures.• To minimize hazardous situations.• To correct deterioration.• To modify plants.• To generate safe working conditions.• To obtain on grade products.• To increase productivity.• To reduce wastage of material & parts.• To reduce manufacturing cost.• To add in high quality & economical operation.

NEED FOR MAINTENANCE

Maintenance is a key element in the

organisation’s value chain

INCREASES CASHMARGIN

BUSINESSOBJECTIVES

INCREASES SALESAND REVENUE

INCREASE RESERVES

REDUCES OPERATING

COSTS

INCREASESPRODUCTION

HIGH FACILITY

AVAILABILITYCOST EFFECTIVE MAINTENANCE

BREAKDOWN MAINTENANCE

• This is a PANIC or CRISIS maintenance

• It is not desired at all in today's environment

TYPES OF MAINTENANCE

BREAKDOWN MAINTENANCE

• BATH TUB CURVE– Infantile Deaths– Wear-out Stage– Abnormal Operations

• DISADVANTAGES– Uncertain - Occurrence & Repairs – Uncertain Production– Costly Repairs– Unsafe Situation

TYPES OF MAINTENANCE

PREVENTIVE MAINTENANCE

This is a systematic and planned attention, monitoring and analysis. It is most effective if there is strong age related failure mode.

The guiding principle is “Prevention is better than cure”

• Retard process of deterioration and wear• Asses extent of deterioration• Action to restore original capacity• Improve reliability and maintainability of equipment thus

eliminating breakdown

Objectives of Preventive Maintenance

are

TYPES OF MAINTENANCE

• Visual External Inspection• Lubrication Replenishments• Strainer Cleaning• Painting• Adjusting Belt Tension

Preventive Maintenance Programme

PREVENTIVE MAINTENANCE EXAMPLES

TYPES OF MAINTENANCE

ADVANTAGE OF PREVENTIVE

MAINTENANCE• Less down time• Fewer repetitive repairs• Lower repair cost than breakdown repair cost• Superior quality control• Increased life of plant and equipment• Need of standby equipment reduced• Reduction in maintenance cost• Leveled workload and workforce• Better spares control• Enhanced safe working conditions• Increase in production

TYPES OF MAINTENANCE

PREDICTIVE MAINTENANCE

• Online monitoring, measurements, ND testing, etc.• Health of equipment can be predicted with certainty and

necessary corrective actions generated• The result of predictive maintenance can be extrapolated to

determine useful residual life• Leading to prediction of approximate date of failure

By predictive maintenance equipment condition can be known during normal operation through :

TYPES OF MAINTENANCE

– Ultrasonic thickness measurements

– On-line vibration measurements

• Measurement program

– Testing lubricating oil / hydraulic oil

PREDICTIVE MAINTENANCE EXAMPLES

TYPES OF MAINTENANCE

POPULAR PREDICTIVE MAINTEANCE TECHNOLOGY

TECHNOLOGY APPLICATIONS

Iodic vibration analysis• Vibration analysis• On-line vibration analysis• Oil sample analysis• Thermography• Motor stator analysis & elect. • - Surge testing• Motor current signature

analysis• Air borne ultrasonics• Pulse-echo ultrasonics• Process parameters

All rotary equipment• All rotary equipment• Critical rotary equipment• Critical & low speed

equipment• Electrical

components,insulation• Motor stator and insulation • Break down• Motor rotor bars, eccentricity• Steam traps, vacuum leaks• Pipe and vessel thickness• Process or mechanical • Degradation

TYPES OF MAINTENANCE

PROACTIVE MAINTENANCE

• Root Cause Failure Analysis• Precision repairs and installation• Training of maintenance and operational personnel• Review and correct purchase specification

Proactive maintenance is easily integrated with predictive maintenance and completes the platform needed for Reliability Centered Maintenance program

Proactive Maintenance emphasizes on

TYPES OF MAINTENANCE

ADVANTAGES OF PROACTIVE MAINTENANCE

• Repetitive problems that shorten component life are identified and designed out

• This can include standards placed on suppliers for performance acceptability of their products/services, and verification that these are met

• Assuring that equipment installation is done to precision standards (Balancing, Aligning) leading to extended life

• Factors limiting component life are identified and eliminated• Reliability centered maintenance program

TYPES OF MAINTENANCE

TYPES OF MAINTENANCETYPES OF MAINTENANCE

BREAKDOWNMAINTENANCE

PREVENTIVE MAINTENANCE

PREDICTIVE MAINTENANCE

PROACTIVE MAINTENANCE

ROOT CAUSEFAILURE

ANALYSIS

RELIABILITY CENTERED MAINTENANCE

RELIABILITY CENTERED MAINTENANCE