EXAMPLE DIPLOMA PAPER QUESTION (PAPER THREE)
Part A
Explain the measures which are available for assessing the effectiveness of plant maintenance. [10 marks]
PART B
Discuss the constraints and competing demands which may affect maintenance activities. [10 marks]
ANSWER:
Part A
The availability aspect of Overall Equipment Effectiveness (OEE) is important. This is made up of availability, performance, and quality (all 3 important)
% Availability = actual uptime / scheduled runtime x 100
% Performance = Units produced / actual runtime / design capability x 100
% Quality = units produced that are pass specifications (and to note that the amount of quality failures may be symptomatic of maintenance issues).
The measures to be explained in candidates' answer for assessing the effectiveness of plant maintenance are :
- Meantime between failure
- Meantime to repair
- Planned Maintenance backlog
- Compliance to planned hours (schedule)
- Spares stock-outs
- % of Planned Maintenance / Predictive work
- % of corrective maintenance
- % of technician working say hours on “tools”
- Autonomous Maintenance hours worked
- Proactive Work Capacity index (PWCi) = Schedule Compliance x Schedule Load x Tool time. PWCi world class levels = 0.9 x 0.9 x 0.65 = 0.53
It is also important that candidates also explained these above measures with a cost emphasis ie Maintenance cost / unit output &/or Cost as % replacement value
PART B
The constraints and competing demands which need to be detailed in the candidate answer and which may affect maintenance activities are :
- Time:
- Loss of scheduled maintenance time for production
- Slots for extended maintenance work
- Pressure to fix breakdowns temporarily rather than permanently
- Unsocial hours for maintenance
- Regulatory deadlines (e.g. pressure system inspections)
- Cost:
- Labour costs, number of technicians
- Specialist contractors
- Spares stockholding
- Affordability / scope of shutdown work
- Skills:
- Own staff skills
- Specialist skills requirements
- Access:
- Plant availability for the production elements
- Plant availability for shared services / utilities
- Other
- Competing priorities where maintenance resources shared
- Working with inherently unreliable plant which can be de-motivating!
- Agreeing which maintenance activities are appropriate
- Measuring effectiveness
- Motivation of staff