Total Productive Maintenance- Quiz 4
Explain an "OR" gate and an "AND" gate. How do they differ?
"OR" gates are used to indicate that any one of the factors or causes that follow is a sufficient cause and by itself can produce the effect. "AND" gates are used to indicate that all the causes or factors that follow must be present in order for the event to occur. The difference between the two is that only one factor needs to occur for an "OR" gate and all factors need to occur for an "AND" gate.
In performing routine PM, why is the creation of a checklist important?
A checklist is important for PM because it allows for the same things to be done to the equipment every time PM is performed.
What does it mean to say that the maintenance department should be treated as a "profit center" ?
Any unnecessary expenditures that can be eliminated by implementing a sound maintenance program will result in reduction of expense, hence an increase in profit.
Explain some of the applications of ultrasound in predictive maintenance.
Some applications of ultrasound in PDM include using a transducer to emit high frequency ultrasonic waves that are directed toward an object or are used to flood a shell or a part cavity.
Explain the "change analysis" approach to root cause analysis?
The change analysis technique for root cause analysis is based on the assumption that a change in the process, material, procedure, and so on must have occurred in order to cause the problem at hand
How does the level of maintenance commitment affect preventive maintenance and repair costs?
The optimum prevention level is the point at which the total costs are at the minimum.
What are the five pillars of TPM?
The pillars of TPM are planned maintenance, maintenance free, individual kaizen, eduction and training, and self maintenance
What is the purpose of thermography and what role does it play in PDM?
The purpose of thermography is to study various temperatures to detect potential problems in equipment using different methods and tools. In PDM, thermography can be used to locate "hot spots" and their possible sources.
Ideally, what percent of the total maintenance activities should be preventive?
ideally, all maintenance activities should be preventive
Define preventive maintenance
preventive maintenance: A series of predefined and scheduled maintenance activities that are designed to reduce equipment break-down, increase equipment reliability, and improve productivity.
What is a fault tree?
A fault tree is a diagram that allows you to see all the causes, their relationships, and the necessary conditions that can result in a failure. Fault trees are used as a troubleshooting tool to gain insight into an existing problem.
What is meant by a system of criticality and what do the various criticality codes mean?
A system of criticality is a system that classifies equipment based on the degree to which the equipment and its failures are considered to be critical. Criticality Code I: No backup, will cause harm, stop production Criticality Code II: Breakdown undesirable but. not drastic, slow-down in production, might cause harm Criticality Code III: Doesn't seriously affect normal operation, won't cause harm
Explain some of the methods of evaluating alternative solutions.
Alternative solutions may be evaluated on the basis of implementation costs, feasibility, return on investment, ease and difficulty of implementation, constraints and limitations, and the probability that the given solution will be successful in removing the hazard or eliminating its future occurrence.
How would an Ishikawa diagram help with a root cause analysis?
An Ishikawa diagram can help with root cause analysis because it can be used to represent the relationship between an event and its causal factors and it helps in identifying all the possible causes for a problem.
How can oil analysis help in PDM?
An oil analysis can help in PDM because it can inform operators of potential problems or failures that could occur as a result of contamination of lubricants.
What are some of the basic PM activities and why are they important?
Basic PM activities include cleaning, lubricating, and inspecting. They are important because a problem can be detected before it turns into a major catastrophe.
How does benchmarking help a company improve their methods and practices?
Benchmarking helps a company improve their methods and practices by allowing the company to compare their procedures to those of the best and learn from the best, implementing how they do things in their own procedures.
Define CMMS and explain the importance and the roles of CMMS in modern maintenance management.
CMMS: Computerized maintenance management systems - Used for maintenance management planning and control - Roles include staffing, effective planning and scheduling of events, ability to track and control backlog, creating and tracking equipment history and work orders
What are the advantages and disadvantages of centralized versus decentralized maintenance departments?
Centralized Advantages - better utilization of human and equipment resources - overall backlog can be controlled - better control of inventory of special equipment and material Disadvantages - Time lost in traveling among various locations - Scheduling can be cumbersome - Less supervision of maintenance crew Decentralized Advantages - Various departments have their own maintenance departments - Faster response to maintenance needs - Better supervision of crew Disadvantages - duplication of personnel, special maintenance equipment, and material, which increases inefficiency and cost
Why is cleaning considered to be the most important step in equipment maintenance?
Cleaning is the most important step in equipment maintenance because it provides an understanding of the machine, it plays a role in identifying contaminants and their sources, and it keeps the equipment in like-new condition.
What are the three types of maintenance activities and how do they differ from each other?
Corrective maintenance: The required repair work after the equipment failure has occurred. Preventive maintenance: takes steps to prevent and fix problems before failures occur. Predictive maintenance: Predicts possible failures using statistical tools and various instruments and tests, such as vibration analysis, chemical analyses of lubricants, thermography, optical tools, and audio gauges.
What is design of experiments (DOE)? Do you see an overall relationship between DOE and maintenance functions?
Design of experiments (DOE) is a technique that isolates a series of variables that the experimenter might suspect to be influential in a given process, then systematically manipulates these variables and their settings to determine what variables and at what settings would be optimal for the process. The relationship between DOE and maintenance functions is that the DOE will determine the root cause analysis and in turn determine what maintenance functions need to be performed.
Why are economic considerations important in planning preventive maintenance activities?
Economic considerations are important because as increase in the level of PM equals an increase in the total cost level.
What is meant by "empowerment" and what role does it play in TPM?
Empowerment signifies a sense of ownership of the operators' equipment. It makes the operator feel like they have control over their equipment. The operator can play a key role in TPM by doing basic routine activities including cleaning, lubricating, and inspecting.
What is the importance of maintaining equipment history in order to have a viable PM program?
Equipment history is important because it aids in determining equipment reliability, MTBF, and equipment availability. It also can point out failure trends and causes of failures.
What is an "events and casual factors analysis" and what does a butterfly flapping its wings have to do with anything, anyway?
Event and casual factors analysis is a systematic approach to examine events, their sequences, the conditions under which these events occurred, and any factor that might have resulted or caused that event.
For an organization to be considered world class, what level of its maintenance activities should be of a predictive nature?
For an industrial organization to be considered world class, one-third of all maintenance activities on average need to be predictive in nature.
It has been said that those who practice benchmarking are doomed always to be the second best. How would you agree or disagree with this statement?
I disagree because you can learn from the best and then expand on their practices, which may put you over the top, making you the best.
What is the NDT technique used in the predictive maintenance process in Japanese nuclear power plants discussed in the case study?
In the case study, the nuclear power plants in Japan used the technique of Eddy current testing in their predictive maintenance process.
What is infrared and what role can it play in PDM?
Infrared imaging is one of the most versatile and widely used methods for detecting surface temperature variances caused by abnormal or uncharacteristic conditions. Infrared imaging can be used to discover leaks in pipes and other sources of energy and material loss.
What is the purpose of irreversible temperature labels?
Irreversible monitoring labels have the ability to maintain the highest level of surface temperature for future reference.
How is magnetic particle testing used to detect surface cracks in objects?
Magnetic particle testing is used in the detection of cracks in the surface of objects by studying the imaginary lines of force formed around a magnetized steel bar. A crack in the surface of the object will disturb the lines of force and each side of the crack will behave as separate magnets, forming opposite magnetic poles on each side of the crack.
State and briefly explain some of the primary objectives of the maintenance department.
Maintaining existing equipment timely and appropriate response to equipment failure, reduction of downtime, increase equipment availability Equipment inspection, cleaning, and lubrication develop program for operators to do routine tasks to detect problems before they occur, develop schedule for regular and routine cleaning and lubrication Equipment modification, alteration, and installation non-routine activities, so can be scheduled during slack periods to increase efficiency of maintenance personnel Utility generation, distribution, and management maintenance and efficient operation of steam, electricity, etc. Maintaining existing buildings and grounds building repairs, painting, etc. Building modification and alteration plant expansions, process changes
What is meant by "maintenance backlog," and would you recommend keeping the backlog at or near zero level? Explain your answer.
Maintenance backlog generally can be defined as how much has to be done. Keeping the backlog at or near zero level is not recommended because the maintenance personnel will be idle when no repairs need to be made. An average backlog of two to three weeks is recommended.
Define: a) maintenance b) failure
Maintenance: All activities necessary to keep a system and all its components in working order. Failure: Any deviation or change in a product or system from a satisfactory working condition to a condition that is below the acceptable or set operating standards for the system.
Would you recommend the use of magnetic particle testing for the detection of surface cracks in an aluminum object?
No, aluminum would not be recommended for magnetic particle testing because aluminum is not magnetic.
Explain NDT and state some of the techniques that are used in PDM.
Nondestructive testing (NDT) involves methods of testing and evaluating material properties in order to detect defects in engineering structures without impairing their future use of altering the integrity of the material. Some of the testing techniques used in PDM are ultrasonic, thermography, radiography, Eddy current, liquid penetrant, magnetic particle, and holography
What is OEE and what are the factors affecting it?
OEE is overall equipment effectiveness. The factors affecting it are availability, efficiency, and quality
What role does Pareto analysis play in root cause analysis?
Pareto analysis generalizes root cause analysis by stating that in most cases, 80% of the downtime is caused by failures in only 20% of the equipment.
Planning for maintenance should begin at what stage of the product life? Explain.
Planning for maintenance should begin at the design stage. Through proper design, the need for and frequency of some maintenance activities can be drastically reduced and many functions can be simplified.
Define predictive maintenance and contrast it with other types of maintenance.
Predictive maintenance applies to various technologies and analytical tools used to measure and monitor various system and component operating characteristics and to compare these data with established and known standards and specifications in order to predict system or component failures, whereas corrective maintenance is applied after the failure, and preventive maintenance uses precautionary measures to avert possible problems
Define root cause analysis. What is the significance of root cause analysis in maintenance?
Root cause analysis is a systematic approach in identifying the basic or the root cause of a problem or an undesirable condition so that actions may be taken to eliminate the cause and prevent the occurrence of the undesirable event. Root cause analysis can be related to maintenance in the sense that it aims to identify the causes of potential failures and prevent them in the process.
What are some of the fundamental concepts of TPM?
Some fundamentals of TPM are to avoid the crisis in the first place and to shift the ownership and responsibility for the equipment and its upkeep to the operator.
What are some of the factors that determine the acceptable levels of vibration for a given piece of equipment?
Some of the factors that determine the acceptable levels of vibration for a piece of equipment are size, stiffness, and weight of the equipment, the rigidity of the base on which it is mounted, and the surrounding equipment.
What are some PDM methods?
Some of the methods of PDM are vibration analysis, chemical analysis, thermography, ultrasound techniques, radiography, radioscopy, and magnetic particle testing.
What are some of the potential failure modes affecting your calculator? What effects could these failures have?
Some potential failure modes affecting a calculator are that it will not perform math functions correctly, buttons could become jammed, and so forth. Effects that these failures could cause might include failing an exam because your calculator malfunctioned, you get the wrong answers, and so on
What is TPM and what role does it play in the overall productivity of a company?
TPM is a corporate-wide equipment and resource management strategy for overall quality and productivity improvement. Its goal is to increase overall productivity.
TPM programs strive to reduce and eliminate six significant obstacles to achieving full equipment effectiveness. State and briefly explain the obstacles and how TPM addresses each of them.
TPM programs strive to reduce and eliminate six significant obstacles to achieve full equipment effectiveness : 1. Equipment failure: Reduce equipment breakdown 2. Setup and routine adjustments: Increase equipment utilization 3. Idling and stoppage: Trained operator can detect and remedy routine causes of abnormalities and slowdowns 4. Reduce speed: trained operators will be able to detect the deviations between expected and actual speeds. 5. Defects: scrap and defects due to out-of-control conditions can be recognized and corrected 6. Startup problems: recognize and correct problems associated with achieving a stable process
What is the basic blueprint set forth by AT&T for benchmarking?
The basic blueprint set forth by AT&T for benchmarking is as follows: a. Conception: which areas would benefit from benchmarking? b. Plan: Establish goals and objectives of benchmarking and create a plan. c. Collect data: Collect data on current process and practices d. Identify best in class: Who is best? e. Collect data on best practices: How do these companies achieve their status? f. Compare: Compare your practices and processes with those of the best. g. Implement: Plan to incorporate their practices into your own operations and procedures. h. Evaluate: Assess your success
What are the eight pillars of maintenance?
The eight pillars of maintenance are support and guidance for operator self-maintenance activities, reduction of breakdowns, establishment of planned maintenance activities, lubrication management, spare parts management activities, maintenance cost management activities, maintenance efficiency improvement, and training.
How does the complexity of modern manufacturing systems affect maintenance planning and management?
The increased complexity of modern manufacturing systems highlights the need for a highly skilled maintenance staff and specialized planning, training, and development of programs for maintenance activities and maintenance personnel.
Who is the primary focus of the TPM philosophy?
The operator is the key participant in the TPM environment. TPM utilizes all available resources including operators to improve and maintain equipment. This empowers the operators and allows them to take ownership of the equipment and assume responsibility for basic and routine maintenance activities.
What is the purpose and importance of developing lubrication standards?
The purpose and importance of developing lubrication standards is that the standards ensure that lubrication is performed on a regular basis and they reduce the possibility of error or confusion.
Clearly define and explain the concept of FMEA. What role can FMEA potentially play in TPM?
The purpose of FMEA is to identify potential failures, that is, all the ways in which equipment, a process, or a product can fail, attempting to determine how these failures can or may affect the overall operation of the equipment or the entire system, and to propose solutions or a course of action to eliminate these potential failures. The role that FMEA can play in TPM is that is trains and educates the operators on how to handle potential problems that they encounter while on the job effectively.
Predictive maintenance is said to be quantitative in nature. What does that mean, and how does that differ from PM?
The quantitative nature of predictive maintenance means that data are collected, analyzed, charted, and interpreted, and vital decisions are based on these data. This differs from PM because PM is scheduled maintenance to prevent failures, whereas PDM uses data to predict when a failure will occur.
What role does CPI (continuous process improvement) play in TPM?
The role that continuous process improvement (CPI) plays in TPM is to reduce setup and manufacturing cycle times, reduce and simplify material handling and inspection, and eliminate and minimize work in process.
Based on a full understanding of the concept of FMEA, how would you rename FMEA?
The word "potential" should be added, to make it potential failure mode and effect analysis
How would you relate Deming's concepts of TQM to the culture of TPM?
They both include ideas of empowerment and improvement for the company as a whole. They both also stress the importance of training and education.
Explain what is meant in this chapter by the statement that if the workers are not part of the solution, they will be part of the problem.
This means that everyone needs to know and understand why and how the problem occurred and the necessary measures needed to correct the problem or they may be the reason that the problem occurs again.
Define tribology and explain its significance in PDM
Tribology is the science and technology of friction, lubrication, and wear. It significant in PDM because understanding and controlling friction aid in material and energy conservation
How does vibration affect the useful life of a product?
Vibrations can significantly reduce the useful life of a product because excessive vibration can cause rapid equipment deterioration.
What is meant by workplace organization and what is its significance in TPM?
Workplace organization means that there should be an appropriate place for every part, tool, and so on, and every item must be placed in the appropriate location. Workplace organization plays an important role in quality and productivity.
Under what general category of NDT does X-ray technology fall, and what are some of its industrial uses in PDM?
X rays are in the radiography category of NDT. Some of there industrial uses in PDM include evaluating the condition of forgings, welds, castings, and many other metallic and nonmetallic fabricated parts.
Do you think that TPM can be implemented in a union environment? What are the implications?
Yes, TPM can be implemented in a union environment; this can be seen by examples at AT&T, DuPont, and Ford Motor Company, to name a few examples
State and briefly explain some of the secondary functions of the maintenance department?
plant protection and security salvage of obsolete equipment and waste disposal pollution and noise control ADA, EPA, OSHA, and other regulatory compliance
To what NDT technique does the "oil-and-whiting" technique refer?
refers to is liquid penetrant. this method works by first cleaning the test object to remove any oil, dirt, or other material that would interfere with the action of the penetrant. The liquid penetrant is then applied to the test object. The liquid penetrant usually contains some sort of dye. The penetrant is then given sufficient time to permeate the surface cracks and openings. The object is then wiped clean and a developer is added to the surface. The developer draws the penetrant to the surface , which makes the cracks visible.
What does the discovery of silicone in oil indicate?
that there is airborne dirt in the oil
What is TPM?
the continuous and overall improvement in equipment effectiveness through the active involvement and participation of all employees.
What is meant by "design for maintainability"?
the product should be designed so that maintenance functions are easy to perform. This is because the more difficult the maintenance function, the more likely it will not be done, or will not be done correctly.
Define benchmarking
to search for the best in class and learn from them
In planning maintenance activities, what are some factors that the scheduler must consider?
when scheduling maintenance activities, the scheduler must consider the priority of various tasks, the amount of time required for completion, the type of tools, equipment, and labor needed, and the size and skill of maintenance crew needed.