(SEM VII) THEORY EXAMINATION 2024-25 MAINTENANCE ENGINEERING & MANAGEMENT

SECTION A

(2 × 10 = 20 marks | Short Answers)

a) Maintenance planning

Maintenance planning is the systematic scheduling and organization of maintenance activities to ensure equipment reliability with minimum downtime and cost.

b) Objectives of maintenance

Maximize equipment availability                              Reduce breakdowns

Ensure safety                                                             Minimize maintenance cost

Improve equipment life

c) MTBF (Mean Time Between Failures)

MTBF is the average operating time between two consecutive failures of a repairable system.

MTBF=Total operating timeNumber of failuresMTBF = \frac{\text{Total operating time}}{\text{Number of failures}}MTBF=Number of failuresTotal operating time​ 

d) Role of maintenance economics

Maintenance economics helps in optimizing maintenance cost by balancing preventive maintenance, breakdown cost, spare parts, and downtime losses.

e) Routine maintenance

Routine maintenance includes regular inspection, cleaning, lubrication, and minor adjustments carried out daily or weekly to prevent failures.

f) Eight pillars of TPM

Autonomous maintenance                                       Planned maintenance

Quality maintenance                                                 Focused improvement

Early equipment management                                  Training and education

Safety, health & environment                                    TPM in administration

g) Condition monitoring

Condition monitoring is the continuous or periodic measurement of equipment parameters to detect early signs of failure.

h) Use of correction monitoring

Correction monitoring helps in detecting deviations from normal operating conditions so corrective actions can be taken before breakdown occurs.

i) Age-dependent failures

Failures whose probability increases with time or usage due to wear, fatigue, or corrosion are called age-dependent failures.

j) Unpredictable failures

Failures that occur randomly without prior warning, often due to sudden overload or manufacturing defects.

SECTION B

(Attempt any 3 | 10 marks each)

a) Maintenance organization structures

Centralized: All maintenance handled by one department

Decentralized: Maintenance at departmental level

Combined: Mix of both

These structures ensure better control, faster response, and cost efficiency.

b) Maintenance categories                             Breakdown maintenance

Preventive maintenance                                 Predictive maintenance

Corrective maintenance

Selection depends on equipment criticality, cost, downtime impact, and safety.

c) Instruments used in Condition Monitoring

Vibration analyzer: Detects imbalance, misalignment    Thermal camera: Identifies overheating

Oil analysis: Detects wear particles                               Ultrasonic detector: Finds leaks and bearing faults

d) Repair methods for machine beds

Scraping                                                                 Grinding

Metal stitching                                                       Epoxy resin filling

These restore alignment, rigidity, and precision.

e) Hydraulic and pneumatic equipment in material handling

Hydraulic lifts                                                          Pneumatic conveyors

Actuators and valves

Maintenance includes leak inspection, lubrication, pressure checks, and filter cleaning.

SECTION C

Q3 (Attempt any one)

a) Economic efficiency through maintenance planning

Proper planning reduces unexpected breakdowns, downtime losses, spare inventory cost, and improves machine utilization and productivity.

b) Corrective vs Preventive vs Predictive maintenance

Predictive maintenance is most cost-effective in the long run.

Q4 (Attempt any one)

a) Fixed time vs Condition-based maintenance

b) Role of FMEA

FMEA identifies potential failure modes, their causes, and effects, helping prioritize preventive actions and improve reliability.

Q5 (Attempt any one)

a) Cost factors in Condition Monitoring

Equipment cost                                              Training cost                                     Data analysis cost

CM reduces breakdown losses and downtime, making it cost-effective compared to reactive 

maintenance.

b) Temperature-sensitive tapes

These tapes change color at specific temperatures, helping detect overheating in bearings, motors, and electrical panels.

Q6 (Attempt any one)

a) Importance of failure analysis

Failure analysis identifies root causes, prevents recurrence, and improves machine life.
Steps:                                                               Data collection

Inspection                                                        Cause analysis

Corrective action

b) Logical fault location

It uses systematic elimination techniques to trace faults step-by-step, reducing repair time and guesswork.

Q7 (Attempt any one)

a) Repair methods for material handling equipment

Welding                                                              Replacement of worn parts

Lubrication                                                          Alignment correction

These ensure smooth operation and longer service life.

b) Downtime minimization

Using job order systems, preventive schedules, trained manpower, and quick-response repairs reduces equipment downtime.