Total Productive Maintenance. -
September 22nd, 2008
Small Theory on Total Productive Maintenance:
Total Productive Maintenance.
TOTAL PRODUCTIVE MAINTENANCE
We expect our machines to work without failures, produce high quality output, at the same time consume very less manpower, raw materials, electrical energy, tools/ consumables etc, but this is highly difficult to realize in practice unless they approach is towards identifying the losses and eliminating them. Total productive maintenance, shortly termed as TPM, provides means to achieve and maintain high levels of productivity.
TPM is based on zero loss concept, viz. zero accidents, zero defects and zero breakdowns, which render equipment “effective”.
TPM focuses on improving the Planned Loading Time. The gap (losses) between 100% and actual efficiency can be categorized into 3 categories:
- Yield (Quality Rate)
Breakdowns and changeovers indicate situations where the line is not running while it should be.
Speed losses and small stops/idling/empty positions indicate the line is running, but is not providing the quantity it should.
Additionally, when the line producing products, there are losses due to rejects and start-up quality losses.
Total productive maintenance:
Aims at getting the most efficient use of equipment.
Establish a total PM system encompassing maintenance prevention, preventive maintenance and improvement-related maintenance.
Involves every employer in the company. It requires the co-operation of equipment designer and engineers, equipment operators and maintenance workers.
Promotes and implements PM small through small-group or team activities.
BRIEF ON 8 PILLARS
AUTONOMOUS MAINTENANCE: (JISHU HOZEN)
Autonomous maintenance is the cleaning, checking, discovering hidden faults and undertaking simple adjustments by the operators, systematically trained through a step by step program. Autonomous management is to prevent reoccurrence of the defects by taking pre-emptive action by the operator. “This is my machine and I must maintain it” is the underlying philosophy of autonomous maintenance.
o A typical autonomous maintenance follows step-by-step process as under:
1. Training to create awareness for equipment cleaning among the circle members.
2. Preparation of cleaning schedule.
3. Model equipment cleaning by section manager.
4. Elimination of dirt, dust and oil spillage.
5. establishing basic equipment condition-
6. Improving hard to clean, hard to inspect and hard to lubricate.
7. Counter message to avoid reoccurrence.
8. Preparation of cleaning standard.
9. Preparation of lubrication standard.
10. Preparation of general inspection check list.
11. Preparation of process inspection check list.
12. Preparation of autonomous maintenance check list.
13. Auditing of JISHU-HOZEN activities at every step
14. Motivation by reward schemes.
Kobetsu-kaizen is to continuously improve utilization of workers, equipment and material through continuous improvement in the process and procedures etc.
o It analyses the various causes of time losses and evolve solution to the chronic problems.
1. Break down losses
2. Setup and adjustment losses
3. Idling and minor stoppage losses
4. Speed losses.
5. Quality defect and rework loss
6. Start up losses.
o Step involved to develop kobetsu kaizen are:
a) Select equipment/line/process
b) Organize project teams
c) Collect loss data summaries present losses
d) Draw kaizen themes
e) Set targets
f) Analysis and recommendation by the team
g) Display result
o Benefits of kobetsu kaizen are reflected in reduced
1. equipment failures
2. equipment breakdowns
3. job change time
4. toll change time
5. minor stops
6. management losses
7. manufacturing cost
Planned maintenance is to achieve “zero breakdowns” by improving the efficiency of traditional preventive maintenance activities.
o Planned maintenance encompasses three forms of maintenance:
(i) Corrective maintenance to repair, adjust or replace unsatisfactory equipment operation.
(ii) Preventive maintenance to repair, adjust or replace unsatisfactory equipment to prevent future occurrence of breakdowns.
(iii) Predictive maintenance to replace fault Paris prior to failure without affecting production by predicting a failure before it occurs with enough time to be able to make arrangement. Predictive maintenance makes use of different condition monitoring techniques.
o Planned maintenance aim at-
Focusing “planned maintenance” rather than “break down”.
Achieving stable production by eliminating
Supporting autonomous maintenance.
Increasing mean time between failure (MTBF)
Reducing maintenance cost.
Activities involved are-
1. Maintenance of equipment condition
Nut/bolt tightening and small fixing.
2. Maintenance of operating condition
Set design capacity
Standardize operating method
Set environmental condition
3. Restoring deterioration
Daily check points
Calendar based check points
Shutdown based check points
4. Improving design weakness
5. Skill improvement
6. Reliability based maintenance
Review of equipment maintenance
Failure pattern and failure analysis
Reliability based assessment
7. Maintenance cost control
Improving life of equipment
Change of supplier
Rebuilding and reconditioning
Improving maintenance practices
Spare part control
o Benefits of planned maintenance are:
Zero equipment failures and break downs
Reduced maintenance cost.
QM is to prevent quality defect by
a) Incorporating quality into product through process and equipment rather than controlling quality by inspecting products and taking action against defects after they have occurred.
b) Maintaining perfect machine and tooling condition so that defective are not produced.
c) Setting and maintaining optimal process condition to get quality product.
d) Preventing occurrence of defect by periodic measurements and verification of standards.
e) Taking counter measurement.
Quality maintenance pillar focuses on four production inputs:
o Activities under quality maintenance embraces following activities:
1) Preparation of quality assurance matrix
2) Identifying co-relation between quality variation and conditions
3) Implementation of quality maintenance systems
4) Preparation of quality charts
5) Evaluation of problems severity by using failure mode and effect analysis
6) Using team approach to track down root causes of the problem
7) Assessing the impact of the proposed counter measures
8) Implementing of the improvements in the current process technology
9) Training of customer for right product application.
o Benefits of this pillar are-
Reduction in customer quality complaint
Reduction in inspection time
Reduction in process defects
M.P.DESIGN AND EQUIPMENT CONTROL
Maintenance prevention design and initial equipment control is designed to facilitate
a) Most efficient investment aimed at achieving vertical start upon full production
b) Design of equipment which is highly functional, easy to maintain and which does not fail.
c) Shorten the period of development.
d) Achieve low life cycle of equipment.
o Activities involved
1. Initial investment control by preparing block sanction report effective equipment investment along with scheme for early start up.
2. activities to study weakness of present equipments.
3. preparation of MP design sheets for feeding the information design to enhance the equipment reliability and maintainability.
4. feed MP design information to sister units.
5. life value analysis for costly spares/equipments.
EDUCATION AND TRANING
Since success of all other pillars of TPM depends opon the success of education and training, this is one of the pillars which has direct linkages to other pillars. The aim of education and training under TPM is-
1. To develop talent in equipment maintenance and
2. To develop skills for zero defects, zero breakdowns and
3. to develop abilities to discover and analyze malfunctions
and improve equipment functioning
4. to have multi-skilled employees in all departments
The following activities can be placed under this pillar:
1. workers skill level assessment in 4 categories to identify
their class room as well as ‘on the job (ojt) training’
-can do well
2. setting training targets
3. preparing annual training calendar
4. development of in-house training facilities
5. development of on-the-job training workshops
6. depute employees to outside training programmes on
7. post training evaluation to access effectiveness.
Office TPM is to eliminate problems in the non-shop floor areas so that offices are oriented for excellent support for manufacturing. Typical office problems analyzed under office .TPM are: non availability of files / documents in time, lengthy meetings without agenda, poor house keeping, insufficient storage, high inventory, slow manual working, duplicate work, etc.TPM aims at :
Improvement in filing system.
Reduction in product inventory.
Increase in office productivity.
1: 5 ‘S’ Implementation.
2: Improved filing system for easy accessibility and quick retrieval within X (say 45) seconds.
3: Building up a system of administrative autonomous maintenance.
4: Improving administrative capacity through education and training.
5: Creating an efficient staffing system.
6: Office automation and computerization to achieve paper-less office.
7: Establishing inventory standards and control system.
8: Speedy communication system.
Safety, hygiene and environment control
Safety, hygiene and environment control is to identify and eliminate all hazards by adopting safety, hygiene and environment friendly activities to prevent death, disability, injuries and occupational diseases at work.
TPM is one of the best tools to enhance safety at work place through small group activities and involvement at all levels of organization for common goal of “zero activities” and “zero pollution”
TPM aims at –
Zero occupational disease.
Following activities can be placed under this pillar :
1. Safety and environment policy.
2. Safety related activities.
- preparation of safety manual
- safety audits
- implementation of safety work permit system
- introducing safety award scheme
- display safety poster and slogan
- regular monitoring and analyses of accident cases
3. Pollution control related activities.
- initial environmental review
- elimination of leakage ,spills, dust etc
- up gradation of existing pollution control equipments
- tree plantation
- creating awareness of environmental control through classroom lectures
- regular environmental audits.
4. Detection of problems that may affect safety
5. Hygiene audits.
STEPS PROCEDURE FOR IMPLEMENTATION OF TPM
STEP 1: Declaration by top management to introduce TPM
STEP 2: Introductory education and campaign for TPM.
STEP 3: Create organization to promote TPM
STEP 4: Setting basic policy and targets for TPM
STEP 5: Preparation of master plans for implementation TPM
STEP 6: TPM kick-off
STEP 7:Total application of TPM and raising its level
Lack of knowledge of the TPM.
Low education level of Indian workers
Resistance to change
Apathy towards “Jishu –Hozen” which involves initial
cleaning up by senior staff.
Fear of loss of job.
Fear of extra work load.
BENEFITS OF TPM
TPM can result in following benefits to the organization
Greater equipments availability
Low production cost
Development of employees
Greater employee involvement due to small group activities
Few customers complaints
Few industrial accident
Improved workers morale
Clear distinction between responsibility and authority
Improved companys competitive strength