Operations Management Maintenance and Reliability Chapter 17 Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Outline GLOBAL COMPANY PROFILE: NASA THE STRATEGIC IMPORTANCE OF MAINTENANCE AND RELIABILITY RELIABILITY Improving Individual Components Providing Redundancy MAINTENANCE Implementing Preventive Maintenance Increasing Repair Capability TOTAL PRODUCTIVE MAINTENANCE TECHNIQUES FOR ESTABLISHING MAINTENANCE POLICIES Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Learning Objectives When you complete this chapter, you should be able to : Identify or Define: Maintenance Mean time between failures Redundancy Preventive maintenance Breakdown maintenance Infant mortality Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Learning Objectives - continued When you complete this chapter, you should be able to : Describe or Explain: How to measure system reliability How to improve maintenance How to evaluate maintenance performance Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

NASA Maintenance of space shuttles Columbia: Maintenance requires 86,000,000 miles on odometer 3 engines each the size of a VW expected to make dozens more launches Maintenance requires 600 computer generated maintenance jobs 3-month turnaround More than 100 people Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Maintenance Management All activities involved in keeping a system’s equipment working Objective: Maintain system capability & minimize total costs © 1995 Corel Corp. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

The Strategic Importance of Maintenance and Reliability Failure has far reaching effects on a firm’s operation reputation profitability customers product employees profits Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Maintenance Performance Maintenance Procedures Employee Involvement Maintenance Performance © 1995 Corel Corp. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Good Maintenance & Reliability Strategy Requires: Employee involvement Maintenance and reliability procedures To yield: Reduced inventory Improved quality Improved capacity Reputation for quality Continuous improvement Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Employee Involvement Information sharing Skill training Reward system Power sharing © 1995 Corel Corp. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Maintenance & Reliability Procedures Maintenance Procedures © 1995 Corel Corp. Clean and lubricate Monitor and adjust Minor repair Computerized records Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Maintenance Benefits Lower operating costs Continuous improvement Faster, more dependable throughput Higher productivity Improved quality Improved capacity Reduced inventory Maintenance Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Tactics for Reliability and Maintenance Reliability Tactics improving individual components providing redundancy Maintenance Tactics implementing preventive maintenance increasing repair capabilities Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

System Reliability - Components in Series Average Reliability of all Components (Percent) Reliability of the System (Percent) 100 80 60 40 20 100 99 98 97 96 n=1 n=10 n=50 n=100 n=200 n=300 n=400 Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Reliability of Components in Series R = R1 * R2 * R3 * ... Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Evaluating Maintenance Reliability Probability that an item will function for a given time Mean time between failures (MTBF) Average time between failures of a repairable item Failure rate Reciprocal of MTBF Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Failure Rate (%) Number of failures FR(%) = * 100% Number of units tested Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Lifetime Failure Rates Infant mortality and improper use failure “normal” failure Wearout Failure rate Lifetime Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Failures Per Operating Hour Number of Failures FR(n) = Operating Time Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Mean Time Between Failures 1 MTBF = FR(N) Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Probability of first component working Providing Redundancy Probability of first component working Probability of second component working + Probability of needing second component * = P(R) Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Maintenance Decisions How much preventive & breakdown maintenance Who performs maintenance Centralized, decentralized, operator etc. Contract or in-house When to replace or repair How much to replace Individual or group replacement Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Types of Maintenance Preventive Breakdown Routine inspection & servicing Prevents failures Bases for doing Time: Every day Usage: Every 300 pieces Inspection: Control chart deviations Non-routine inspection & servicing Remedial Basis for doing Equipment failure Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Mean Time Between Failure and Preventive Maintenance Frequency of failure Mean Time Between Failure Candidate for preventive maintenance will have distribution with low variability Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Organizing the Maintenance Function Centralized maintenance department Does all maintenance (PM & breakdown) Decentralized maintenance department Useful if different equipment used in different areas of company Contract maintenance Used if little equipment or expertise Operator ownership approach Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Operator-Ownership Approach Operator does preventive maintenance Equipment condition is their responsibility Learns equipment better Increases worker’s pride Reduces repair time & PM costs Maintenance department is backup Handles non-routine problems Provides maintenance training Has plant-wide responsibilities Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

A Computerized Maintenance System Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Maintenance Costs Traditional View Maintenance Commitment Cost Preventive Maintenance Cost Total Maintenance Cost Breakdown Cost Optimal Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Maintenance Costs Full Cost View Optimal Total costs Full cost of breakdowns Preventive maintenance costs Maintenance Commitment Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Contract for Preventive Maintenance Compute the expected number of breakdowns without the service contract Compute the expected breakdown cost per month with no preventive maintenance contract Compute the cost of preventive maintenance Compare the two options Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Increasing Repair Capabilities:Features of A Good Maintenance Facility Well-trained personnel Adequate resources Ability to establish a repair plan and priorities Ability and authority to do material planning Ability to identify the cause of breakdowns Ability to design ways to extend MTBF Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Operations Manager Must Determine How Maintenance Will be Performed Operator Maintenance Department Manufacturer’s field service Depot Service (return equipment) Competence is higher as we more to the right Preventive maintenance costs less and is faster as we move to the left Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Total Productive Maintenance Additional requirements of: Designing machines that are reliable, easy to operate and easy to maintain Emphasizing total cost of ownership when purchasing machines, so that service and maintenance are included in the cost Developing preventive maintenance plans that utilize the best practices of operators, maintenance departments, and depot services Training workers to operate and maintain their own machines Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

A Key To Success High utilization of facilities, tight scheduling, low inventory and consistent quality demand reliability - total preventive maintenance is the key to reliability. Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458

Techniques for Establishing Maintenance Policies Simulation - enables one to evaluate the impact of various maintenance policies Expert systems - can be used by staff to help diagnose faults in machinery and equipment Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458