Concepts of Total Productive Maintenance - Topic - 6 : Steps of Jishu- Hozen (JH Pillar) -Part 3

Jishu-Hozen Pillar Step 1 : Initial cleaning and inspection

In continuation to my previous blog posts, "Steps of  Jishu-Hozen Part 1 and Part 2",(Links : Steps of JH Part 1 and Steps of JH Part 2), where we have discussed in detail about Jishu- Hozen pillar  a, its steps of implementation and Step -0 of Jishu Hozen i.e. Preliminary step of preparatory step, here in this blog we will discuss on the Step -1 of Jishu-hozen, i.e. Initial cleaning and inspection of machine. The step is Explained below :

Step -1 : Initial Cleaning , Inspection :

Fig. 1. Operator Cleaning his own equipment

The literal meaning of the word "Cleaning Activity", includes the activities of removal  of dusts , stains , oil blots, machined chips and burs, cut powder, sludge, scale, ruct and other foreign unwanted matters or particles that gets deposited on the machine / equipment, that makes the machine or equipment untidy and unfit for work. These cleansing is an important step before machine starting and enables the operators also to find the opportunity of potential malfunction and potential defect creation during operation. While cleaning operators gets to know or is able to discover points of leakages, loosening and damage, gets to know about the actual state of essential machine running parameters such as oil level, pressure check, sensor functions, abnormalities related to jig or fixture mountings, potential hazards and many more things. Here machine or equipment cleaning does not target for, just exterior appearance improvement, it also calls for a keen checkup of all essential parameter. Hence in Jishu- Hozen or autonomous maintenance, cleaning process also includes inspection, or in other words, "Cleaning is Inspection".


Hazards or problems arising from insufficient cleaning is shown in the below tabulated form:

Table 1. Hazards or problems arising from insufficient cleaning

In Jishu- Hozen, cleaning and inspection process must go hand in hand. It is not rare, that in a fully equipped production line, or a large size manufacturing setup, nearly 200 to 500 abnormalities can be observed when cleaning is conducted in every part of machine / equipment.

During the initiation of Jishu- hozen  the operators must be trained on the cleaning procedure and cleaning equipments. Inspection must be carried out during machine / equipment cleaning. The major points that needs to be worked on and / or the points that must get addressed at the time of Step 1 of Jishu Hozen i.e cleaning and inspection are illustrated in following steps -

• Adequacy of Training :  Complete training must be given to the operators and they should be personally engaged in cleaning. They should learn to treat cleaning and inspection as a part of their own work responsibility. 
• Verification of Safety checkpoints : The operator must check and ensure the safety aspects are in place before initiating the cleaning process and even during conduction of cleaning activities. The operator must be equipped with right PPE's and cleaning apparatuses. During cleaning the operators must check safety curtains, sensors, safety guards, performance and connections of alarms and buzzers etc. The operators may also take photographs before going for cleaning activity.
• Standardise cleaning process : The operators must be given training on standardised cleaning and inspection process. Supervisors or line in-charges must ensure that the operators are observing / following the standards.  CLIT is a commonly used term in standardisation of cleaning process which stands for Cleaning, Lubrication, Inspection and Tightening. Some of the commonly used tools in industries are shown below as examples.              

Fig.2. Examples of some cleaning tools used commonly in industries

• Identification of "Hard to access" points and "sources of contamination:  :  The operators must know to dismantle the machine / equipment and reassemble it for cleaning purpose. He must open the lids and machine covers by himself and while doing so he should, by himself identify  tough to reach areas or hard to access areas and sources of contamination. The identified "Hard to Access Areas"and "Source of contamination" can be listed as per the below table :                     

Table .2. Register the list of   "Hard to access areas" and enlist the  projects for small group activity

                   

Table 3. Register the list of, "Sources of contamination" and enlist the projects for small group activities.

• Ensuring of complete cleaning : The operator should check and verify complete removal of dirt and dust accumulated over the years in the machine. In the initial stage of JH it is very important. Special focus must be given to the moving parts, rubbing surfaces and other critical areas. Cleaning should be done not only of the machines but also of the ancillary equipment's  such as holders, electrical panels, shifting trolleys, oil tanks, lubricant holder, casings etc. 
• Adherence to the cleaning plan : The cleaning plans must be observed. No parts should be left. The operator must not abandon the cleaning plan assuming, that the equipment will soon be stained or dirtied again as it is brought to use. 
• Inspection along with cleaning : While cleaning the operator also inspect the machine / equipment and keep exposing equipment defects or malfunctions. It is necessary for the operators to know , how to find defects and abnormalities during cleaning and  how to highlight them. There are 7 types of abnormalities in TPM terminology and in Japanese these defects abnormalities are called "Fuguais". The operators must receive training and guidance on ideal and basic condition of machine / equipment and how to identify the abnormalities. The operators needs to learn to use sensing methods correctly to identify abnormalities, an example is given below table : 

Table. 4. Some examples of identification of machine related abnormalities through sensing based inspection

• Some abnormalities are shown in the figure below as an example, which are commonly observed in industry :

Table 5. Some of the frequently observed abnormalities in industries are shown in the figure 

• As it is already been mentioned earlier that the abnormalities are termed as "Fuguai" in Japanese, and there are 7 different types of Fuguai s, explained below - 

  

  Fig. 3. Seven types of Fuguai

• Examples of Seven Types of Fuguai's / Abnormalities   are given below : 
1. Minor flaws : Minor flaws may be related to contamination, damage, play of fasteners, abnormal phenomenon such as noise vibration, adhesion.
2. Unfulfilled conditions : Unfulfilled conditions may be related to lubrication, lubricant supply, oil level gauges, tightening etc.
3. Inaccessible places : Inaccessible places related to cleaning, lubricating, tightening , operation adjustment and inspection.
4. Contamination sources : Sources of contamination may be related to products, raw materials, lubricants, gases, liquids, scrap etc. 
5. Quality defect sources : Quality defect sources may be related to foreign matter, Shock, moisture, concentration viscosity etc. 
6. Unnecessary or non urgent items termed as Unwanted slow moving object : Signifies standby equipments such as additional cooling fans, pipes and connections, additional jigs, tools and spare parts, additional wirings, supporting electrical equipments such as plugs ammeters, voltmeters, coolant or water tanks etc.
7. Unsafe place : Unsafe place may be due to Slippery floor, broken stairs / steps, low light, presence of rotating machinery , old and malfunctioning lifting device.

To further understand the seven types of "Fuguais"or abnormalities please go through my blog post : "7 types of FIGUAI" ( Link : Under preparation)

• Tagging of FUGUAI s : Once the abnormalities are identified Tagging needs to be done on the machine. Along with tagging a data sheet or summary sheet of the tags needs to be prepared which talks about type of FUGUAI, location of FUGUAI, state of malfunction (Such as inclusion of foreign matter, position of inclusion, hard to access locations, sources of contamination and other matters etc.). The tags containing details of the FUGUAIs are attached to the actual points of malfunctions of the equipment so that it becomes easily identifiable  (at which location or part of the machine what kind of abnormality exists. An example is shown in the figure 4.

      

Fig. 4. Identification of abnormalities or FUGUAI on the machine through tagging and analysis of category wise tags

• FUGUAI Tags : Some companies practices having two types of FUGUAI tags and some companies prefer to have 3 types of FUGUAI tags. The tag colour is chosen based on the classification of the abnormalities. 
• Red FUGUAI Tags: They are used to sight those specific machine malfunction/(s) , that needs special attention from a specialist or a maintenance personnel or a contractor personnel or representative of particular machine manufacturer. Production operator or JH circle members (JH CIRCLE- small group of people who are associated with a specific machine or line forms a team do take up improvement projects related to that machine or line.)
• White FUGUAI Tags : They are used to highlight those abnormalities or malfunctions that can be taken be rectified by the machine operators or the JH circle members. A white tag may be attached in case of following abnormalities for example : 
1. Loosening of fitting bolts of limit switches, proximity switches and photoelectric switches.
2. Replacement of worn-off  screws, scattering of cut powders and cutting oils.
3. Dislocation and twisting of movable sections in wiring.
4. Replacement of damaged V-belts, tension springs and loosened chains. 
5. Air and oil leakage due to less tightened bolts, loose joints or loose tube fittings.
6. Replacement of grease cups due to chipping. 
• Yellow FUGUAI Tags : Some companies uses yellow FUGUAI tags to sight the abnormalities or non-conformities related to safe work performance of the machine. Some unsafe conditions and potential unsafe situations are highlighted in these tags. These tags can be mounted by any body (the personnel related to the machine or not does not matter) on the machine. These safety tags are preferably to be closed in consensus with safety officer or  a safety expert of the machine. Operators along with maintenance personnel may be involved in closing the abnormalities or malfunctions highlighted in the safety tags (yellow FUGUAI tags). 

Fig. 5. Red, White and Yellow FUGUAI tags, needs to be attached to the locations of machine / equipment where minor abnormality and malfunction has been observed.

• Based upon these tags a list of abnormalities (shown below) and a abnormality tag matrix (shown below) can be prepared for further analysis. Five types of abnormality highlighted in the FUGUAI tags must be removed or eliminated by operation personnels. These five types are - Minor flaws, unfulfilled basic conditions, quality defect sources, unwanted and slow moving objects, unsafe conditions. For the other two categories of abnormalities i.e. Sources of contamination and Hard to access areas (HAA) the operation team may seek support form maintenance personnel or maintenance staff. So the key to success is the cooperative action jointly taken by operations team and maintenance team. As a matter of fact, at a higher level of maturity among operating staff(generated due to high level of involvement in JH activity) results in such scenarios where the operators may propose the improvements and the maintenance staffs are often involved in executing the suggested repairing activity. 

  

  Fig. 6. Removal of 5 types of FUGUAI 

• The FUGUAI tags needs to be reviewed time to time as per the standard frequency set by the organization. Once an abnormality or cause of malfunction is eliminated from the machine or equipment, the relevant tags must be removed from the machine. The tags needs to be stored and a running tag register needs to be kept so that the related history of abnormality and malfunctions of the machine / equipment can be referred in future. 
• As a part of common industrial practice the red FUGUAI tags are removed (i.e. abnormality is eliminated) with in 7 days from the date of tagging and white tags are removed with in 48 hours (maximum two days) form the date of tagging. The Safety FUGUAI tags are to be removed only after taking consensus of Safety personnel or relevant responsible person. Note :There is no such guideline which specifically mentions about the target time of tag removal. But most of the industries makes a standard for it so that the abnormalities does not last for a longer time and operator does not run the machine / equipment with abnormalities for long time.

Table 6. Example formats to identify and highlight list of abnormalities in machines or equipments 

Table 7. Abnormality tag matrix for analysis of the abnormalities appeared on a particular machine over a period of time. This is used for analysis of frequency of recurrence based on particular time frame for a specific machine or equipment.

• Documentation of Step 1 of Jishu -Hozen : To summarise the 1st step of Jishu-Hozen i.e. "Initial Cleaning and Inspection", some documentations are needed to be done and the formats are needed to be filled holistically. The documents are - 

1. List of abnormalities or FUGUAI s
2. List of malfunctioning or foul parts
3. List of hard to access areas
4. List of sources of contamination 
5. Abnormality Matrix
6. Status of FUGUAI tags - machine wise 
7. Why why analysis of abnormalities or FUGUAI s 
8. List of countermeasures and their implementation status for "5 types of abnormalities" (Abnormalities which are responsible for forced deterioration). 

These documentations and activity trackers are to be regularly updated and audited for effectiveness. A small description of Jishu-hozen step 1 audit is given in the next point.

• Auditing of stage 1 of Jishu Hozen implementation : At the end of stage 1 of Jishu hozen stage i.e. " Initial Cleaning , Inspection" tentative cleaning standards are prepared, based on observations made from "List of minor defects", " List of hard to access areas", "List of sources of contamination", " List of sources of quality defects", "List of unnecessary or non-urgent items" and " List of unsafe conditions and hazards". These lists are prepared during the first time cleaning and inspection only. Managers are involved along with operators to decide the machine restoration and improvement standards. List of activities during initial cleaning and post cleaning are decided and a diagnosis is done. TPM activity boards are prepared for visual display of trends of abnormality and small improvement groups re formed to drive improvement initiatives. All these standardisation calls for an audit to verify sufficiency and effectiveness of Stage 1 of JH. The stage 1 Audit can be done in layered audit approach i.e. Self Audit, Department Audit, and management Audit. Score targets may be decided for each layer of Audit (an example is given below). An Standard Audit check sheet can be used for audit purpose. An example format is shown only to give a flavour. Note : No specific standard audit check sheet or audit process is recommended any where. Individual Organisations always may have their own standards in terms of auditing practice depending upon their way of working. Following layered audit approach and audit check sheet is shown just for referring as examples.

Fig. 7. A sample layered audit structure (for example ) may be adopted 

A diagnosis or audit check sheet as a sample is shown below:

Table 8. A sample of  JH Stage 1 (i.e. Initial cleaning and inspection stage) audit or diagnosis check sheet for reference

 Hope you will like the detailed explanation given above in terms of implementing JH Stage 1 i.e. Initial cleaning and inspection stage.  The next step is, " Step -2 : Countermeasures against Sources of contamination and hard to access areas (Link : Under preparation).

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... to be continued!