Total productivity maintenance drives the thought of participation by every stakeholder in the production facilities i.e., it drives the idea that not only the team who manages or maintains the production, other teams or facilities should also participate in the maintenance activity (E.g., participation from leadership till operators)
The total productivity maintenance work on goals like zero-defects/error, zero-accident/incident, zero-shut down/outage
To manage each goals there are 8 strong and effective pillars on which the concept of total productivity maintenance is established. The pillars are:
1. Continuous improvement
2. Autonomous maintenance
3. Preventive maintenance
4. Training and education
5. Startup monitoring
6. Quality management
7. Administration
8. Health & safety management
All these 8 pillars of TPM works on the lean tool of 5 S (Sort, Shine, set in order, standardize & Sustain)
One of the key pillars of TPM is Autonomous maintenance also known as Jishu Hozen in Japanese where basically it means independent (Jishu) maintenance through management, protection & veracity (Hozen) by all the stakeholders from top layer management to the workers on the field
Jishu Hozen in manufacturing is usually used to upscale the operator to make a daily effort to maintain the performance of equipment and processes during the issues identified in the equipment/tool/machine without waiting for the expert or technical support to resolve.
In normal practice if there is a layer of hierarchy or many departments with scope of work defined, one department would wait for the other interlinking department to bring the solution, however the user of the equipment would know in and out about the equipment and should take charge to maintain them instead of waiting for action from other department i.e., operator should be empowered to maintain the equipment taking responsibility of the equipment. The frequent user of the equipment can generally inspect and identify if there is any functional issue, maintain the equipment through cleanups and frequent oiling or lubrication due to which the performance of the equipment can be enhanced & capacity improved.
JH shifts the attitude from I, to WE leading to improvement in equipment productivity, efficiency and enhances the skills of the user/operator leading to cultural shift
•Manage equipments:
•a) Cleaning, b) Identifying flaws/errors,c) Optimizing efficiency,d) Restore to old status
•Understand equipments:
•a) Functionality,b) Monitor-frequent checkups,c) Optimizing efficiency
The ownership and accountability need to jointly be handled by all layers of the organization.Largely there are 3 layers of management: Upper layer, Middle layer and Lower layer
How JH works?
The equipment when purchased has a life span as per the tested laboratory outcome. Beyond the available lifespan the performance of the equipment deteriorates if it is not maintained properly. Such weakened performance could be due to improper handling of the machine. Both these scenario are interlinked as :
a) If the equipment is not maintained properly (by Lower layer of management) the machine would have to be replaced with new leading to huge cost of capital and such decision need to be taken by the middle and top layer of management
b) If the equipment needs to be managed well by lower layer of management it would involve additional cost of maintenance like more cleaning, lubrication, minute repair from inspection etc. which should be budgeted by top and middle layer management
Performing both the action would lead to improvement in the life span of the equipment.
Preventive maintenance is essential part of JH where equipment is inspected regularly to see if there are abnormalities observed and address them on priority to avoid equipment to be a scrap if such issues remain un-actioned leading to increase in cost and dip in the quality/perforance of outcome from the equipment. In order to perform the inspection , checklist is the key document to be maintained at operator’s level and to be managed day to day.
If AM(JH) is properly management by the operators, the need of technical staff is restricted to the annual maintenance of the equipment and/or during the complete shutdown/break of the equipment. Such scenario is not only observed in the manufacturing industry but also in areas like
a) Domestic equipment’s (Fridge, washing machine, TV, Mobile phones & other gadgets are maintained by user and user seek technical help only during extreme stoppage conditions or annual maintenance)
b) Infrastructure support & service (VPN connectivity, Network support, application & password management etc. are managed by the user following the self-help user manual and the technical support is consulted during complete shut down or update/upgradation/renewal)
To ensure the successful implementation of JH we need to ensure:
Audit can be conducted to check if the JH is implemented successfully at multiple layers of management
e.g Self inspection, Audit at function/department level, Audit at the leadership head level
Following checkpoints for implementing the successful JH
On implementation of JH we can ensure
a) A team is identified to perform JH -Training imparted, Expectations set, Plan etc.
b) Cleaning- Precautions taken to clean, use kit, Prioritization etc.
c) Address issues in equipment-Understand impact, identify source, define frequency of identification
d) Establish standard of JH- Preparation of inspection, visually control and monitor, checklist
e) Conduct general inspection-Draft schedule, inspection manual/process, identify abnormalities
f) Autonomous inspection-Monitor quality/time take/output, Correct abnormalities, follow inspection training and standard module
g) Standardize-eliminate waste, check proper flow managed
h) Complete independent autonomous management-Streamline routine, enhance operator problem solving skills, perform continuous improvement through company goal alignment,
The successful implementation of JH can be measured using the calculation of overall equipment effectiveness (OEE) parameter. The operational metric of OEE is as follows:
OEE = Availability rating X Performance rating X Quality rating
A)Availability rating is calculated in %, indicating the % of time the equipment was available for usage and calculated as:
Availability rating =( (Available time – Shut down or Break time)/Available time)*100
E.g if a machine is available for 1000 hrs and there was breakdown for 100 hrs then availability rating will be ((1000-100)/1000)*100= 90% Availability rating
Performance rating is calculated in %, indicating what is the performance or outcome of the equipment vs what was planned
Performance rating = (Actual production/Planned production) *100
E.g if the planned or target for production was 1000units and actual production is 900 units then performance rating will be (900/1000)*100=90% performance rating
C) Quality rating also measured in% indicates the level of quality of the output i.e Accuracy %
Quality rating = (Number of defect free part of output/Total produced output or production)*100
E.g if the total production is 900 units of which defect free are 890 units then quality rating will be (890/900)*100 = 98.88%
So, Overall equipment effectiveness = Availability rate X Performance rate X Quality rate =
(0.9*0.9*0.98)*100 = 79.83%
Such OEE is tracked and measured in a set frequency like weekly, fortnightly, monthly, quarterly etc and expectation is that OEE should have gradual increase indicating the effective implementation of Jishu Hozen. The more the OEE % the better is JH implemented