Total Productive Maintenance and Reliablity

Description
This is a presentation describes on the importance of Maintenance, different maintenance cost models, reliability issues of equipments, TPM, different activities to be performed in TPM, TPM development stages and steps.

MAINTENANCE

Agenda –

? Maintenance
? Introduction to Reliability

? Total Productive Maintenance (TPM)

Maintenance –
Objectives :
• To enable product and service quality, and customer satisfaction through healthy equipments • Maximize useful life of the equipments • Prevent unsafe working • Minimize process variability • Reduce the operational attributable to the equipments • Minimize frequency and severity of equipment interruptions • Maximize the productive capacity of the equipment resources

Why Maintenance is critical ?
• Following JIT – can not tolerate outages • Operational cost is one of the key differentiators • Machine would work only if people work • Ever increasing dependence on technology and machines due to higher levels of automation • Specialized technology calls for specialized maintenance skills • A good maintenance system can result into an effective inventory control for spare parts • Maintenance is no longer viewed as reaction to machine breakdowns, the role is to participate in quality and productivity enhancement

Types (Phases) of Maintenance –
• Breakdown Maintenance (Pre 1950s) – to set the machine right when in trouble • Preventive Maintenance (1950s) – establish a maintenance system to improve machine performance • Productive Maintenance (1960s) – recognizing importance of maintenance (1960s), reliability (1962), maintainability engineering (1962) and economic efficiency (engineering economy)

• Total Productive Maintenance (1970s) – productive maintenance efficiency through a comprehensive system based on respect on individuals or total employee participation

Maintenance Decisions –
• Centralized vs. Decentralized Departmentalization – general or specific skills, physical location, etc. • In House vs. Outsourced System – cost factors, convenience, skill required, etc.

• Standby Equipments – cost of maintenance (of the main as well as stand by), time for maintenance, need for reliability, etc. • Repair vs. Replacement – cost factors, performance assurance, etc.

Maintenance Decisions –
Preventive Maintenance vs. Remedial Repair –
• Relative Cost
Total Cost Cost of preventive maintenance

Cost

Cost of downtime & repair or Breakdown cost Level of prevention



Life Span (refer Bath Tub Curve)

Maintenance Cost models –
With no preventive maintenance, the total cost of per period is ?CRN where CR is the repair cost and N is the number of identical machines With preventive maintenance, the total cost TC = CPM + CRB1, where B1 = M x P1, M is the number of identical machines and P1 is the probability of machine undergoing breakdown after first period of its preventive maintenance For period (or say month 2) the expression would be B2 = M(P1 + P2) + B1P1 (since we mean the cumulative probability) Total Cost TC = CPM + CRB2 , we can get the average cost as TC / 2.

Reliability issues of equipments –
MTBF – mean time between failure MTBF = ? iP i
n
i

(MTBF is expressed in terms of expected value) where, ‘P’ is probability that the machine would run without a failure, and ‘n’ is the maximum period that a machine will go without failure MTTR – mean time to repair

Reliability issues of equipments –
Reliability is the inverse of probability of failure Bath Tub Curve –
Infant Mortality or Burn in (startup failure period) Useful Life or Chance Failure Period Wear out Failure Period

No. of failures

Time

Total Productive Maintenance (TPM) –
Productive maintenance involving total participation

The definition involves :
a. Maximization of equipment effectiveness (Overall Equipment Effectiveness – OEE) b. System for maintenance for entire equipment life c. Involves various departments / functions

d. Involves every single person from top to shop floor
e. Based on motivation and small group activity

Total Productive Maintenance (TPM) –
Overall Equipment Effectiveness (OEE) : OEE = Availability x Performance Efficiency x Rate of Quality Products Availability = Operating Time / Total Machine Time = (Total Machine Time – Downtime) / Total Machine Time Performance Efficiency = Net Operation Rate x Operating Speed Rate

Net Operation Rate = Actual Processing Time / Operating Time
= Processed Amount x Actual Cycle Time / Operation Time Operating Speed Rate = Ideal Cycle Time / Actual Cycle Time

Rate of Quality Product = Quality rate or fraction accepted
So even of the availability, performance efficiency and rate of quality product are 90% (individually), OEE = 0.9 x 0.9 x 0.9 = 0.729 or about 73 %.

Total Productive Maintenance (TPM) –
TPM Development : Activities to be performed 1. ? ? ? ? ? ? 2. 3. Eliminate 6 big losses to improve equipment effectiveness – Equipment Failure Set up and Adjustment Idling and Minor Stoppages Reduced Speed Defects in Process Reduced yield Install an autonomous maintenance programme, and A schedule maintenance programme

?

Journey from Preventive Maintenance to Autonomous Maintenance Autonomous Maintenance involves – basic cleaning, source of problems, setting cleaning & lubrication standards, general inspection of the equipment, autonomous inspection and organization and orderliness

Total Productive Maintenance (TPM) –
TPM Development : Activities to be performed

3.

Improve skills of operation and maintenance personnel – By education and training

4. ?

Initiate equipment management programme – Function analysis

?
?

System design
Cost analysis, etc.

Total Productive Maintenance (TPM) –
TPM Development Stages and Steps :

Stage 1 : Preparation

1. 2. 3. 4. 5.

Announce top management’s decision to introduce TPM Launch educational campaign to introduce TPM Create organizations (committees, etc.) to promote TPM Establish basic TPM policies and goals Formulate a master plan for TPM development

Total Productive Maintenance (TPM) –
TPM Development Stages and Steps :

Stage 2 : Preliminary Implementation

6.

Hold TPM kick off

Total Productive Maintenance (TPM) –
TPM Development Stages and Steps :

Stage 3 : TPM Implementation

7. 8. 9.

Improve effectiveness of each piece of equipment Develop an autonomous maintenance programme for operators Develop scheduled maintenance programme for the maintenance department

10. Conduct training to improve operation and maintenance skills 11. Develop early (immediate response) equipment management programme

Total Productive Maintenance (TPM) –
TPM Development Stages and Steps :

Stage 4 : Stabilization

12. Perfect TPM implementation and raise TPM levels for achieving higher goals

Total Productive Maintenance (TPM) –
TPM Small Group Activities

? ?

As a part of organization structure To work on the company goals

?
? ?

Formal, generally headed by a supervisor
A permanent body within the department (Different than Quality Circle – Japanese concept)

Total Productive Maintenance (TPM) –
TPM Small Group Activities Stages Stage 1 : Self Development by learning and motivation Stage 2 : Identification of Improvement Projects and Implementation

with a sense of achievement
Stage 3 : Problems selection to complement the company goals and problem solving

Stage 4 : Autonomous Maintenance by selecting higher levels of
goals consistent with corporate policy and manages to work independently on them

Total Productive Maintenance (TPM) –
TPM Small Group Activities

How to make it a success ?

Individual

:

Self Motivation
Ability

Management

:

Creation of a favorable environment

SESSION ENDS



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