The Good Maintenance Guide

1. The Good Maintenance Guide 1. Introduction

2. 1. Maintenance Management 1.1 Definitions (1) Asset • Any item of physical equipment

3. 1. Maintenance Management 1.2.Definitions (2) Asset function • - What users expect from their assets • (output, speed, safety, environmental • integrity, quality ..) • - The level of performance which the • users require when the asset does • its function

4. 1. Maintenance Management 1.1. Definitions (3) Asset failure • Situation where the asset is no longer capable of fulfilling one or more of its intended functions

5. 1. Maintenance Management 1.1. Definitions (4) Maintenance • Any activity carried out on an asset in order to • - ensure that the asset continues to • perform its intended functions • - repair the asset

6. 1. Maintenance Management 1.1. Definitions (5) Maintenance management The coordination, control, planning, execution and monitoring of the right equipment maintenance activities of manufacturing operations

7. 1. Maintenance Management 2. Objectives • Preserve asset functions • Avoid the consequences of failure of the asset • safety failures: endanger personnel and equipment • operational failures: result in product loss and cost of repair • non-operational failures: result in cost of repair

8. 1. Maintenance Management 3. Evolution (1) Definitions • Availability • time available for production - downtime time available for production • = a measure of the equipment uptime • Reliability • the probability that equipment will not fail in a given time period • = a measure of the frequency of downtime

9. 1930 - 1950 1950 - 1980 1980 - 2000 Higher availability Lower costs Longer asset life Higher reliability Better product quality Safety integrity Environment integrity Show results 1. Maintenance Management 1.3. Evolution (2) Expectations of the maintenance function Fix it when it breaks Higher availability Lower costs Longer asset life

10. 1930 - 1950 1950 - 1980 1980 - 2000 Condition monitoring Failure modes and effects analysis Computerized Maint. Management Systems RCM - TPM (see later) 1. Maintenance Management 1.3.Evolution (3) Maintenance techniques Fix it when it breaks Scheduled maintenance Planning systems Computerization

11. The Good Maintenance Guide 2. Maintenance Management Functions

12. 2. Maintenance Management Functions2.1. Overview • Physical asset management • identification of assets • recording of information Maintenance strategy conducting the right maintenance Maintenance planning & scheduling work order management • Resources management • people, spare parts, tools • Performance measurement

13. The Good Maintenance Guide 2. Maintenance Management Functions Physical assets management

14. 2. Maintenance Management Functions2.2.Physical Assets Management Maintenance is concerned with Assets • Preservation of asset functions • Renovation of assets • Life extension of assets • Replacement of assets

15. Maintenance Management Functions2.2.Physical Assets Management • Assets must be identified • use an asset hierarchy to identify your assets • example • plant • area (packing area) • equipment (belt conveyor) • item (gear box) • part (bearing) • standardize the equipment descriptions

16. Maintenance Management Functions2.2.Physical Assets Management • Asset information must be recorded • record all equipment maintenance activities • assign all maintenance costs • establish and effectively use a documented history for each equipment

17. The Good Maintenance Guide 2. Maintenance Management Functions Maintenance strategy determination

18. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance type Strategy Fix it when it fails Emergency maintenance Corrective maintenance Preventive maintenance Time based (calendar time or running time) Condition based Predictive maintenance Equipment redesign Modification maintenance Failure finding Routine maintenance

19. Maintenance Management Functions2.3.Maintenance strategy determination How can we assure that the maintenance conducted is the right maintenance and that it produces the required equipment reliability? Reliability Centered Maintenance (RCM)

20. Maintenance Management Functions2.3.Maintenance strategy determination RCM is a technique for reviewing equipment failures and for determining the right maintenance tasks RCM definition

21. Maintenance Management Functions2.3.Maintenance strategy determination RCM properties • RCM ensures that all performed maintenance is cost effective • RCM contradicts the traditional precepts that the reliability of equipment is directly related to operating age • RCM focuses on preserving the functions of equipment, not on preserving the equipment itself

22. Maintenance Management Functions2.3.Maintenance strategy determination RCM steps • Select the most critical equipment • Determine the functions of the equipment • Establish performance standards • Determine type of failures • Identify causes of failures • Define effects of failures • Categorize the effects of failures • Identify appropriate maintenance tasks • Establish an overall maintenance plan

23. Maintenance Management Functions2.3.Maintenance strategy determination RCM implementation • Operations • identifies the functions and performance standards • Maintenance • identifies the types of failures • defines the most appropriate condition monitoring techniques • builds a program • Maintenance and operations • collaborate on the consequences of identified failures • carry out the program

24. Maintenance Management Functions2.3.Maintenance strategy determination Some important notes about failures • A part of equipment has suffered a failure when it is no longer capable of fulfilling one or more of its intended functions • A failure mode or cause is any event which causes a failure • A failure pattern is the relationship between the probability of failure of an item, and its age • There are six distinct failure patterns, one of which is the bathtub curve

25. Maintenance Management Functions2.3.Maintenance strategy determination Bathtub curve Probability of failure Manufacturing & installation defects Useful Life Period Wear-out Period Operating time

26. Maintenance Management Functions2.3.Maintenance strategy determination Failure patterns A (bathtub curve) - starting with manufacturing and installation defects, going to constant failure probability, ending in a wear-out zone - example: new machines

27. Maintenance Management Functions2.3.Maintenance strategy determination Failure patterns B - constant failure probability, ending in a wear-out zone - example: abrasion

28. Maintenance Management Functions2.3.Maintenance strategy determination Failure patterns C - slowly increasing probability of failure - no identifiable wear-out age - example: fatigue

29. Maintenance Management Functions2.3.Maintenance strategy determination Failure patterns D - low failure probability when the item is new - rapid increase to a constant level

30. Maintenance Management Functions2.3.Maintenance strategy determination Failure patterns E - constant failure probability at all ages - example: rolling element bearings

31. Maintenance Management Functions2.3.Maintenance strategy determination Failure patterns F - starts with high failure probability - drops to a constant level

32. Maintenance Management Functions2.3.Maintenance strategy determination • The most appropriate equipment maintenance strategy can be determined by • The failure pattern that applies to a given failure mode • Mean Time between Failures (MTBF): the number of failures in a given time period, divided by the time that the equipment was operating in that period • FMEA (Failure Mode and Effects Analysis): identify all the events which are reasonably likely to cause each failed state

33. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance types: emergency maintenance • Definition: • maintenance work requiring immediate response from maintenance employees • Goal: • solve downtime, safety risk, danger or damage • Properties: • unplanned • creates peaks and valleys in the work load • expensive • requires emergency spare parts purchasing

34. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance types: corrective maintenance • Definition: • restoring an asset to a preserved condition • Goal: • improve quality or performance • Properties: • planned • a work order has been created • the work is prepared

35. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance types: preventive maintenance • Definition: • replacements or overhauls scheduled on elapse of calendar time or elapse of running time • Goal: • reduce downtime and breakdowns • extend the life of the equipment or system • Properties: • planned & prepared • correct failure probability must be known • original reliability must be restored

36. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance types: routine maintenance • Definition: • short periodic work carried out pre-dominantly on-line • ex: inspections, lubrication, adjustments • Goal: • reduce downtime and breakdowns • extend the life of the equipment or system • Properties: • planned & prepared

37. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance types: predictive maintenance • Definition: • comparing the trend of measured physical parameters against known engineering limits • Goal: • detecting potential and hidden failures (see next slide) • Properties: • planned • condition based

38. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance types: predictive maintenance • Types of failures • functional failure: the inability to meet the specified performance standard • potential failure: a physical condition which indicates that the failure process has started (metal particles in oil) • hidden failure: failure is not apparent until the function is attempted

39. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance types: predictive maintenance The majority of failures do not occur instantaneously but develop over a period of time (P-F Curve) . . 100% Failure can be detected Failure starts to occur P Operating Condition . Failure has occurred F Time - Possible actions at P - prevent functional failure - avoid consequences of the failure

40. 2. Maintenance Management Functions2.3.Maintenance strategy determination Maintenance types: predictive maintenance • Diagnostic devices: • Vibration analysis • Lubrication analysis • Infrared thermography • Ultrasonic testing • Shock pulse methods • Oil analysis • Coolant analysis • Wear particle analysis

41. The Good Maintenance Guide 2. Maintenance Management Functions Maintenance planning and scheduling

42. 2. Maintenance Management Functions2.4.Maintenance planning and scheduling Definitions • Work request • formal request to have work done. • Can be filled out by a production or maintenance employee • Work order • Written authorization to proceed with a repair or other activity to preserve an asset function

43. 2. Maintenance Management Functions2.4.Maintenance planning and scheduling • Work planning • assigning work orders to a time period • plan resources • Work scheduling • arranging the sequence of the work orders • considerations • priority • availability of craftsperson • availability of material and equipment • desires of the operating personnel

44. 2. Maintenance Management Functions2.4.Maintenance planning and scheduling Workflow • Work identification • by operation or maintenance personnel • Work order creation • work order number • date • originator • asset identification • short description • priority • approved by

45. 2. Maintenance Management Functions2.4.Maintenance planning and scheduling • Work preparation • accounting code • job description (sequence of events) • crafts required • material required • tools required • safety and environment considerations • estimated hours

46. 2. Maintenance Management Functions2.4.Maintenance planning and scheduling • Work execution • Progress tracking • Work analysis • Recording information • nature of occurrence of the failure • nature of the failure • nature of the repair • total downtime, labor-hours and spare parts

47. 2. Maintenance Management Functions2.4.Maintenance planning and scheduling Work preparation • Work preparations are important • facilitate estimation • assure that the job will be done in the most efficient manner • contribute to training by indicating the methodology of the job • the preparation can be used the next time the job has to be executed

48. 2. Maintenance Management Functions2.4.Maintenance planning and scheduling Priority system • A priority system is established to ensure that the most needed work orders are scheduled first • Example of priorities • 0: emergency or safety work • 1: work to start within 24 hours • 2: work to start within 1 week • 3: work to start within 1 month • 4: turnaround or overhaul

49. 2. Maintenance Management Functions2.4.Maintenance planning and scheduling Backlog management • What is Backlog: • all work available to be done. Backlog work has been approved and prepared • The backlog must be used as a tool to make decisions • informs management about future needs for maintenance (contracting, more or less personnel) • must be effectively managed so that it does not grow to an unmanageable size

50. The Good Maintenance Guide 2. Maintenance Management Functions Resource management