Principles of Industrial Maintenance PDF

Course materials provided for personal study only and subject to the disclaimer on the ECU website http://www.ecu.edu.au/supplemental/disclaimer Principles of Industrial Maintenance...

Course materials provided for personal study only and subject to the disclaimer on the ECU website http://www.ecu.edu.au/supplemental/disclaimer Principles of Industrial Maintenance Lecturer: Dr Ana Vafadar [email protected] Upcoming activities Slide 2 ⚫ Case Study Group Formation (Week 4) Students should form a group (typically, 3 to 4 persons in each group) List of projects and group formation link are already given. Groups should be formed by Friday 15th of March 2024. Otherwise, the groups will be formed randomly by the unit coordinator. ⚫ Online Review Test 1 (Week 5) Due on Thu 21st March 3:00 PM Perth, WA time zone (UTC+8) Test link will be available for 2 days before the above-mentioned time. Review of modules 1- 3 (1) Fundamental approaches to maintenance (2) Preventive maintenance (3) Predictive maintenance Principles of Industrial Maintenance Edith Cowan University 2018 This lecture ⚫Coverage in this lecture will be largely derived from … Stephens, M. P. (2010) Productivity and reliability-based maintenance management. New Jersey: Pearson Education, Inc. (ISBN 9781557535924). Content from other sources will be indicated where applicable. This lecture – the plan ⚫This lecture material is largely based on … Preventive Maintenance (CHP 3) (Stephens, 2010) 3.1 Preventive Maintenance 3.1.1 Routine Preventive Maintenance 3.1.2 Major Preventive Maintenance 3.2 Equipment History 3.2.1 Establishing and Updating History 3.2.2 Determining Reliability, MTBF and Availability 3.3 Establishing A System of Criticality 3.3.1 Three Degrees of Equipment Criticality 3.4 Planning for Preventive Maintenance 3.5 Design for Maintainability This lecture in a nutshell ⚫This lecture will basically … Identify various activities that make up preventive maintenance: Routine (preventive maintenance) Major (preventive maintenance) Highlight the significance of well-documented equipment history for effective preventive maintenance Look into the concept of system (failure) criticality  Fundamental Approaches to Maintenance Slide 6 ⚫Defining Maintenance A typical relationship between the level of maintenance, repairs and costs is … total cost optimal level preventive maintenance cost cost breakdown maintenance cost maintenance level Adapted from Fig 3-1: Stephens (2010) Principles of Industrial Maintenance Edith Cowan University 2018 Preventive Maintenance Slide 7 ⚫An Introduction to Preventive Maintenance (PM) One approach that can be adopted to reduce the costs associated with Corrective Maintenance (CM) is to invest in (some level of) Preventive Maintenance (PM). The main mechanisms by which increased PM affects the CM are two … More preventive maintenance reduces the likelihood of sudden failure More preventive maintenance lessens the severity of failures Increased investment in PM can results in the two following productivity gains … Increased uptime (reduced downtime) Better equipment utilization and efficiency The costs associated with PM rise as its implementation becomes wider … Some of this increased cost may be alleviated through improved productivity PM Unit cost likely will drop over time. A build up of experience and resources leads to the potential of better efficiency Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 8 ⚫An Introduction to Preventive Maintenance The shape of the relationship between PM (level) and breakdown cost may vary. The form of this relationship will influence total maintenance costs (see below). Available data indicates that a PM programme may occupy ~50% of total costs (invested) in maintenance activities. Compare this ratio to less than 20% for CM. The relationship PM2 between cost and optimal level PM may take on different trends. There can be different “optimal” Preventive levels for the total maintenance cost of combined cost CM+PM programme. cost PM1 breakdown maintenance cost maintenance level Adapted from Fig 3-2: Stephens (2010) Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 9 ⚫An Introduction to Preventive Maintenance A comparison between “World Class” levels of applying PM and those in North American industry. Type of Industry Actual World Class Assembly 29% 53% Distribution 56% 54% Manufacturing (Large) 29% 51% Manufacturing (Small) 34% 52% Process 34% 42% Consultants’ Opinion 25% 44% Weighted Average 33% 47% Source: Table 1-1. Stephens, Matthew P. (2010) Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 10 ⚫An Introduction to Preventive Maintenance A comparison between “World Class” levels of applying CM and those in North American industry. Type of Industry Actual World Class Assembly 69% 13% Distribution 34% 17% Manufacturing (Large) 61% 19% Manufacturing (Small) 53% 18% Process 50% 15% Consultants’ Opinion 59% 18% Weighted Average 55% 18% Source: Table 1-1. Stephens, Matthew P. (2010) Principles of Industrial Maintenance Edith Cowan University 2018 Fundamental Approaches to Maintenance Slide 11 ⚫Preventive Maintenance Activities PM activities thus constitute a major fraction of overall maintenance related costs. Preventive Maintenance: “… a series of predefined and scheduled maintenance activities that are designed to reduce equipment breakdowns, increase equipment reliability, and improve productivity”. (Stephens, 2010, pg 66) Benefits gained by applying PM include: Greater equipment utilization Longer equipment life Reduced unplanned work stoppage/machine shutdown Better adherence to delivery schedules Improved employer morale (well-tuned machines, less stoppages, ongoing checks, participation in maintenance, better familiarization with equipment) Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 12 ⚫Preventive Maintenance Activities PM activities can be divided into two types: Routine Major Preventive Maintenance Preventive Maintenance  Usually implemented by equipment operator Usually done by dedicated maintenance crews  Activities take relatively short (time) to apply  Implementing these activities usually requires higher skill levels compared to routine activities  Activities are systematically done (they are both routine and scheduled)  Activities take longer time to apply compared to routine activities Examples:  Nature of activities usually requires scheduled machine shutdowns for implementation Cleaning Examples: Inspections Looming failures addressed through planned shutdowns Lubrication Equipment upgrade / modification / calibration + Minor repairs / adjustments Equipment installation Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 13 ⚫Preventive Maintenance Activities - Routine Typical examples of routine PM activity: Cleaning: precedes maintenance related inspections in many cases. Includes: dusting, degreasing and debris removal Other reasons for its implementation: aesthetics, friction reduction, wear prevention Indirect benefits from it: more familiarity by “cleaner” on how equipment functions Lubrication: part of (routine) maintenance activities and typically follows cleaning https://takuminotie.com/ operations. If done routinely, these can help reduce mechanical wear. Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 14 ⚫Preventive Maintenance Activities - Routine Typical examples of routine PM activity: Inspections: sensing faulty parts or operation. Includes: applying all senses and use of instruments Examples: Visible observation: low coolant/oil levels Tactile/hearing: loose parts vibrating What it may also include: https://takuminotie.com/ Faulty gauges, safety interlocks, faulty lights/indicators, leak checking (gas, hydraulic) Minor repairs / adjustments: This may extend to an array of activities not already listed. Includes: Equipment testing Minor equipment adjustments (e.g., bolt tightening) Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 15 ⚫Preventive Maintenance Activities - Major Typical examples of major PM activity: Source: https://www.acornwelding.com/blog/post/what-aircraft-preventive-maintenance/ Equipment dismantling Machine overhauls Worn parts replacement Equipment modification/upgrade May involve equipment maker/supplier Equipment installation Equipment recalibration Test runs Principles of Industrial Maintenance Edith Cowan University 2018 Quiz Slide 16 ⚫ Which of the following item(s) is not (normally) part of the preventive maintenance activities? o Replacing of parts o Checking electrical systems are functioning o Monitoring the equipment condition using all senses and instruments o Monitoring the equipment condition through sensor devices and data analysis o Making major changes o Running tests Principles of Industrial Maintenance Edith Cowan University 2018 Preventive Maintenance Slide 17 ⚫The Role and Necessity of Equipment History How can the routine like cycles of PM activities be established, i.e., how often should these activities be applied? What resources do we need? Establishing what constitutes ‘routine’ periods of PM activity needs requires historical data. Documented equipment history is imperative here. The term ‘documented’ excludes reliance on the memory of maintenance/plant personnel as the basis for identifying equipment maintenance data. Examples: When was the last time the machine was serviced? What were the causes for failure (or the state of condition)? What were the ongoing maintenance costs? Principles of Industrial Maintenance Edith Cowan University 2018 Preventive Maintenance Slide 18 ⚫The Role and Necessity of Equipment History The range of information needed to establish equipment history can extend to include: Period of ownership details… Purchase / installation date … to … decommission date. Additional data … Equipment serial / part numbers Supplier details Installation location Purchase cost Subsequent cost of modifications / upgrades Maintenance / service record Repetitive failures Potential diagnosis of problems Remedial actions implemented / proposed This kind of information can be useful for creating and developing the PM schedule. Principles of Industrial Maintenance Edith Cowan University 2018 Preventive Maintenance Slide 19 ⚫The Role and Necessity of Equipment History The information provided through a well documented and effective register of equipment history allows for deriving … Reliability indicators for equipment Mean Time Between Failure (MTBF) measures Downtime estimates for equipment within a specified date range or (mean downtimes) over a length of time Criteria for the effectiveness of maintenance operations A basis for reviewing and improving maintenance operations More specific analyses of failure causes on equipment (root causes) Comparisons between the ongoing maintenance costs and those for (infrastructure) replacement A primary source of data that can be used to create equipment failure history is information gathered from completed work orders. We will take a closer look at work orders in subsequent lectures Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 20 ⚫The Role and Necessity of Equipment History An example of a data sheet used to log basic equipment history: Source: Figure 3-3. Stephens, Matthew P. (2004) Productivity and reliability-based maintenance management. New Jersey: Pearson Education, Inc. Principles of Industrial Maintenance Edith Cowan University 2018 Preventive Maintenance Slide 21 ⚫The Role and Necessity of Equipment History When does it become more significant to have well documented equipment history ? Establishing equipment history is more necessary (and possible) in some situations: The equipment being targeted is readily identifiable in terms of … location Identifier (part, serial) numbers There is a need/desire to apply PM (or PDM) to these items Data collection and analysis processes are feasible The cost of data collection is justifiable Data collection is useful to other departments Maintenance Accounting The use of computerised methods helps to prepare and maintain complete and accurate data. We will take a closer look at CMMS in subsequent lectures Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 22 ⚫Criticality of System Failure The need to establish well documented equipment histories and subsequently implement service means PM (or PDM) programmes come at a cost. Not all components, parts or equipment in a facility requires a PM program. Different systems and components may not necessarily attract the same level amount of PM (or PDM). This means different systems components or equipment need to be classified based on how critical the consequences of failure may be. How do you classify system failure? What measures do you consider? Principles of Industrial Maintenance Edith Cowan University 2018 Preventive Maintenance Slide 23 Measures of (system) criticality include four: Pieces of infrastructure with a greater (initial) cost will be more likely to System Cost attract PM/PDM compared to those of a much lesser cost Example: Compare between two machines, one costs $500,000 and the other $50,000. not in order of preference A machine that is highly relied upon in a process will be more likely to attract PM/PDM compared to other machines that have less significant functions or Dependence for which there is some degree of redundancy. Example: A general purpose (engine) lathe in 10 similar lathes (of the same size) can be viewed as less critical compared to a similarly priced milling machine (on the same shop floor) where this is only 1 of its kind. Systems for which failure is life-threatening, can lead to injury or property damage are considered more critical and worthy candidates of PM/PDM Safety compared to other systems which are not. Example: Process controls. Systems that have a higher frequency / tendency to breakdown are likely to attract PM/PDM compared to other systems that are not so prone to failure. History Example: An older piece of machinery may necessitate more frequent oil changes compared to another machine that is much newer. Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 24 ⚫Degrees of Failure Criticality Degrees of equipment criticality can be considered when prioritising PM/PDM activities. Degrees of equipment criticality can be defined with feedback from a range of sources including … Maintenance crews Machine operators Plant managers Three Degrees of Equipment Criticality Criticality Code I Source: https://www.123rf.com/ Criticality Code II Criticality Code III The following criticality groupings are only suggested. These may differ based on specific circumstances or applications. Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 25 ⚫Degrees of Failure Criticality - Criticality Code I Criticality Code I: equipment failure may: Cause bodily harm to people Result in environmental hazard Lead to other equipment failing/damage Halt other processes or stop production for prolonged time Create substantial financial loss Stop production because of no backup capacity http://clipart-library.com/ Examples … Conveyor systems that will affect plant operational capability Hazardous material handling equipment / systems PM programmes in Criticality Code I equipment aim to minimise breakdowns. Long term financial losses associated failure in Criticality Code I equipment warrant investment in PM activities. Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 26 ⚫Degrees of Failure Criticality - Criticality Code II Criticality Code II: equipment failure: May be undesired but can be tolerated Will not result in drastic consequences May slow down but for a short duration Can be recovered through the availability of spare parts Can be remedied through some backup, redundant operation capacity or duplication in equipment Examples … A conveyor system that is critical to production; however, its breakdown is not drastic An automatic system that its breakdown may slowdown http://clipart-library.com/ production, but this can be recovered using spare parts. ⚫PM programmes in Criticality Code II equipment aim to reduce the number of breakdowns and shorten the breakdown periods. Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 27 ⚫Degrees of Failure Criticality - Criticality Code III Criticality Code III: extends to equipment for which failure: Does not lead to any serious effect on the normality of operations May occur in equipment that is not frequently utilised Will rarely affect operations PM activities for Criticality Code III equipment can be kept at to a minimum level. PM may be limited to basic routine activities. Cleaning Inspection Adjustments http://clipart-library.com/ Anything beyond basic PM activities for Criticality Code III equipment should be clearly cost justified. Principles of Industrial Maintenance Edith Cowan University 2018 Quiz Slide 28 ⚫ What are two main requirements for developing an effective PM plan ? Well documented equipment history System of failure criticality Principles of Industrial Maintenance Edith Cowan University 2018 Preventive Maintenance Slide 29 ⚫Preventive Maintenance Planning Other than the previously mentioned two requirements, six considerations need to be embodied in planning PM activities. 1. Checklist of required actions and their frequency 2. Identification of who will be the maintenance implementer 3. Listing of what to look for in normal operating conditions: operational temperatures, leakage allowances (if present), acceptable/unacceptable sounds, tightening requirements, normal speeds of operation, wear limits/signs, lubrication needs. The steps and time needed for inspection (for checking these normal operating conditions) should also be specified. 4. Generate reports to show any diagnosed problems and corrective actions implemented 5. Use of short transit routes for maintenance crews 6. Use of PM work orders (forms). These should list: necessary tooling, service equipment needs, consumables and spare parts expected, personnel needs Successful PM plans should also attempt to include participation of all stakeholders, including: equipment manufacturers, maintenance crews, machine operators. Principles of Industrial Maintenance Edith Cowan University 2018  Preventive Maintenance Slide 30 ⚫Design for Maintainability Considerations for maintenance need to be built into equipment from the outset. Source: https://www.colourbox.com/ Poor maintainability designed into equipment can result in … More difficulty in implementing maintenance tasks Greater likelihood for errors during maintenance Longer time frames needed for maintenance Bigger costs associated with maintenance activities Source: https://www.lifecycleinsights.com// Some benefits that can be achieved… Reduction of maintenance steps? Simplification of maintenance tasks? Well documented/standardised service guides? Principles of Industrial Maintenance Edith Cowan University 2018  Slide 31 Thank you Principles of Industrial Maintenance Edith Cowan University 2018