Concept of Material Management for maintenance is different as compared to manufacturing activity. Need of material during maintenance is towards wear & tear, aging and damages and lubricants etc. What material and how much is the essence of material management. With addition of new technologies, different makes and trend of failures makes the material management dynamic which is not very so with the manufacturing process. This brings challenges and a situation of crisis many a times in maintenance organization.
Objective of Material management towards maintenance
Objective of material management is to remove all worn out, defective and aged material from the equipment and replace it with a new one. This responsibility lies with the artisan staff responsible for the work. For him to perform his responsibility efficiently and correctly, following principle shall work
“Availability of the right material at the right time and at the right place is the key objective for maintenance management.”
- Material as per specification and right quantity required for the job assigned for the day.
- When the staff is deputed to perform the work
- Material issued at the time of job assignment or at the time when work is to be performed
- Where the staff has to perform the work and material delivered right at the place where of work
Assessment of Quantity towards maintenance management
Quantity is assessed for annual requirement and called Estimated Annual Consumption (EAC).
- Priority I :
- Identify the items which are subject to continuous wear during service with extensive duty cycle such as brake block, carbon brush, panto-carbon strips, lubricant (mainly due to leakage or overthrowing) etc. These items are those, non-availability of which results out-turn. Yearly assessment is easy based trend of consumption.
- Priority II :
- Identify must change items due to over aging caused by environmental condition in which the equipment works. Yearly assessment is based on overhauling or replacement schedule fixed.
- Priority III:
- Identify items at assembly, component and sub-components level judiciously whether it is economical to replace the sub-component or assembly itself.
- Non-availability will affect out-turn but not immediately using cushion in the life of the component.
- Damaged caused by external factors such as cow run over, external hitting, panto-entanglement etc. Assessment as 2%, 5%, 10%, and 15% of the holding may be made based on experience. It is preferred to repair these items instead replacing by straightening and welding. Considering the basic objective of no-tolerance in reliability and safety, timely replacement is necessary.
- Condition base where the assessment as must change is difficult and the item does not have reliability consequences. Assessment similar to percentage basis shall do.
Tips for Material Management at user-end
- Consider Value Engineering techniques if the annual expenditure is more than the budget.
- The role of maintenance engineer shall not be limited to ensuring availability of material through chasing of Stores Department but towards the totality of objective.
Always remember “Availability of defective material may cause big problems as compared to non-availability of material” It is like entering “WRONG” in the system.
- Empower your staff to assure the quality of material before it goes into the asset.
- The responsibility for asset failure on line lies only with the maintainer so as the identification of defective material before its use on the asset.
- Every precaution shall be taken when the asset is used for conducting trials of a new material
- Over and improper stocking will deteriorate material. Monitor, inspect and correct the procedure. e.g. low value items are purchased for 2/3 years’ consumption since its shelf life is 1/2 years. Staggered supply shall be dictated.
Must Change Items
All equipment provide service during which its parts undergo wear/tear/aging and identified its replacement during overhaul ‘a must’ and called as ‘must change item’.
- Must change items are generally defined by OEM and supplied in a kit form.
- There are many equipment for which must change item is identified but not procured in a kit form as involving more than one supplier. These items are not supplied to the worker in kit form and thus vulnerable to be replaced only on condition basis or partly. These kits shall be formed by the Sectional Supervisor and supplied to work in a kit form and released items taken back for any value engineering.
- Avoid high value items in the most change kit.
Unit Exchange Spares
Ready to use UES is a completely assembled unit ready for replacement and assembled at work place. The work is completed in all respects similar to what we expect from trade suppliers. UES is not a trade supply item.
- Shop floor space management improves considerably. Space for tap changer, MVRH and MPH will not be required when assembled on Transformer. Similarly, with motorized bogies, there will not be any additional space requirement for motor, wheel, gear case, axle box etc.
- Material management improves as non-availability of any material is distanced from locomotive and it will be immediately known as soon as it starts affecting building up Ready to use UES.
- It will help in reducing down time of rolling stock for overhauls.
- Management of executing an action plan improves due to ready availability and ease of working environment.
“Shifting of work management from rolling stock over to Unit Exchange spares is surety to success”.
Annual Maintenance Contract
AMC is extensively used in areas of specialized nature of equipment and jobs involving unskilled nature of work. The specialized nature of works is such where either the in-house staff is not trained or effort made towards training is not sustainable. Job involving mainly unskilled nature of work is based on economic consideration.
User-end role towards quality management in AMC is
- Responsibility for quality through AMC or Works Contract still lies at user end. You may penalize the contractor financially but failure will still be on maintainer account.
- Train and counsel the contractor for quality job
- Material supply may be partly or fully provided in the contract. The quality of material shall be checked beforehand.
- The quality management concept is that ’defect prevention is more helpful and cost effective than defect detection and rework.’
- This concept is very much followed when the work is done departmentally but missed when done through AMC or works contract because redoing cost is charged to the contractor only.
- This thought sometime leads to failure of contract therefore check its quality in time to avoid rework and loss to the contractor
Annual Maintenance Contract is not a new term but was in focus even when the tenders for the construction of Thakurli Power House was invited in the year 1924 with the clause of AMC after the completion of the warranty period. This was the first high technology field over Indian Railways.