IT 381 Midterm

What is meant by "design for maintainability"?

"Design for maintainability" means that the product should be designed so that maint. functions are easy to perform. This is because the more difficult the maint. fucntion, the more likely it will not be done, or will not be done correctly.

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.

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.

PM will find what percentage of problems?

90-95%

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.

Define preventative maintenance

A series of predefined and scheduled maint. activities that are designed to reduce equip. breakdown, increase equip. reliability, and improve productivity.

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 equip. based on the degree to which the equip. and its failures are considered to be critical. Critical Code I: No backup, will cause harm, stop production. Critical Code II: Breakdown undesirable but not drastic, slow-down in production, might cause harm. Crital Code III: Doesnt seriously affect normal operation. wont cause harm.

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.

Calculate the backlog for a 15 person maintenance dept. Assume a 40 hour workweek and 1200 labor hours of maintenance.

Backlog = scheduled hrs. per week/(crew size x hrs./week) Backlog = 1200 hrs./(15 ppl. x 40 hrs./week) Backlog = 2 weeks

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.

What are the adv. and dis. of centralized versus decentralized maintenance depts.?

Centralized Adv. - better utilization of human and equip. resources overall backlog can be controlled better control of inventory of special equip. and material Dis. - Time Lost in traveling among various locations scheduling can be cumbersome less supervision of maint. crew Decentralized Adv. - various dept. have their own maint. dept. faster response to maint. needs better supervision of crew Dis. - duplication of personnel, special maint. equip., and material, which increases inefficiency and cost

Define CMMS and explain the importance and the roles of CMMS in modern maintenance management.

Computerized maint. management systems used for maint. management planning and control roles include staffing, effective planning and scheduling of events, ability to track and control backlog, creating and tracking equip. history and work orders.

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. Preventative 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.

Calculate the crew size for a maintenance dept. in order to maintain a backlog at or near zero level? Explain your answer.

Crew Size = Scheduled labor hrs./(backlog x hrs./week) Crew Size = 1500 hrs/(4 hrs x 35 hrs./week) Crew Size = 10.71 or 11 people

Why are economic considerations important in planning PM activities?

Economic considerations are important because an 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 equip. It makes the operator feel like they have control over their equip. 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?

Equip. history is important because it aids in determining equip. reliability, MTBF, and equip. availability. It also can point out failure trends and causes of failures.

Ideally, what percent of the maintenance activities should be preventative?

Ideally, all maint. activities should be preventative

What is meant by "maintenance backlog," and would you recommend keeping the backlog at or near zero level? Explain your answer.

Maint. 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: maintenance and 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

Planning for maintenance should begin at what stage of the product life? explain

Planning for maint. should begin at the design stage. Through proper design, the need for and frequency of some maint. activities can be drastically reduced and many functions can be simplified.

State and briefly explain some of the secondary functions of the maintenance department.

Plant protections and security. Salvage of obsolete equipment and waste disposal. Pollution and noise control. ADA, EPA, OSHA, and other regulatory compliance.

State and briefly explain some of the primary objectives of the maintenance department.

Primary objectives of maintenance include: Maintaining existing equipment. Equipment inspection, cleaning, and lubrication. Equipment modification, alteration, and installation. Utility generation, distribution, and management. Maintaining existing buildings and grounds. Building modification and alteration.

SSS's of radiography

Schooling, standardization, systems

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? Explain answer.

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 maint. activites.

How does the level of maintenance commitment affect preventative maintenance and repair costs?

The optimum prevention level is the point at which the total costs are at the minimum.

What is TPM?

Total productive maint., the continuous and overall improvement in equipment effectiveness through the active involvement and participation of all employees.

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.

Spectroscopy is a method of what kind of analysis?

chemical analysis