We have a scenario that has risen due to the current economic situation of a high exchange rate for the US Dollar and depreciation of our country’s currency from high inflation. Because of the bad economic conditions, the Letter of Credit provision time has increased significantly as our country’s State Bank is only focussing on critical cases and does not have the budget to cater to all cases.
We have four plants of similar types, and all are almost new. Some 40-50 percent of the plants’ spares are foreign procured items and their purchase depend on providing a Letter of Credit (LC). The delay in getting a LC means the procurement lead time has drastically increased and would impact our plant’s operational integrity due to the non-availability of spares when needed.
Considering the above situation, we must devise a strategy and a proactive plan to live within the current constraints and cater for any unwanted situations.
We are approaching local suppliers, but we have drawbacks, especially for OEM manufactured special parts, with concerns of component availability and their reliability.
We are also thinking of using condition monitoring to extend the parts replacement time based on the actual condition.
Your thoughts are highly appreciated on this concern.
Thanks, and regards,
It is a difficult and challenging situation that your organization faces. As I understand it, around half of your operation’s spare parts face exceedingly long procurement times from overseas suppliers. This is because of the delay in providing a State Bank Line of Credit, as money is restricted due to the exchange rate devaluing and rising inflation of the local currency.
Below are some thoughts quickly put together about how to minimise risks to your plants’ operational integrity during these economic constraints.
1. Operational Workarounds
Pre-emptively chose and prepare workarounds in readiness for potential equipment failures. A workaround is ‘Plan B’ to keep the operation going if an equipment item fails and its repair is delayed.
It might include changing over to another machine; hiring equipment to replace the failed item; installing tie-in and connection points to run piping, hoses, power cables, etc., to bypass the failed item of plant.
2. Interchangeable Parts
Identify what parts in store and in operating equipment are interchangeable with parts in other operating equipment.
It would include checking whether decommissioned equipment parts and second-hand parts can be used in operating equipment.
3. Support from Other Organisations
Research what operating equipment is used in similar organisations in your country, and even in other countries, and contact them where it is practical to arrange access to their spare parts and redundant equipment.
This includes identifying if similar equipment used in your operation is installed in other companies making different products, e.g., the same model pump can be used in dissimilar processes and the spare part for the equipment at one site will be interchangeable with the equipment at the other site.
4. Operating Parts Stress Reduction
Reduce the forces, loads, and stresses suffered by the working parts in equipment at-risk of stopping the operation upon failure. The more that you can lower the stress in a component’s materials of construction the longer that you extend the time to its failure.
This includes reviewing operating procedures and practices and changing to the use of new means and methods of operation that are sure to lower equipment parts’ forces, stresses, and loads.
With regards use of condition monitoring to extend parts replacement time. Be cautious, as condition monitoring (Con Mon) needs a failure to begin and generate an identifiable transmitted signal that is received by the sensor. That signal appears only after the problem being monitored for has already started. To get maximum parts’ service life it is necessary to not have any life-reducing problems in the first place. Do not use Con Mon to detect problems, use it to confirm that the equipment parts are running problem-free and operating at least component stresses.
For example, instead of vibration monitoring for signals of an embryonic bearing failure, you instead monitor for evidence of healthy shaft operating conditions and to confirm the bearing is running correctly in the bearing housing at least stress. By the time the bearing vibration level gets above warning limits, the bearing is already on the path to a breakdown.
Another example is, instead of doing machinery lubrication analysis looking for rising wear particles, changing chemistry, and falling viscosity, you instead monitor to confirm proper shaft alignments, correctly installed and running seals, and the proper interaction of internal components at least operating stresses. By the time a lubrication report tells you there is a problem, your equipment is already suffering rising risk of failure.
5. Apply and Achieve Precision Maintenance Work Quality Standards
Make sure the equipment at-risk of stopping the operation upon failure are at precision maintenance standards of engineering and construction when installed and are not deformed beyond precision tolerance during operation.
By meeting precision maintenance quality standards within equipment, the parts are kept at least stress when in operation, which will thereby decrease the failure rate and lift the equipment’s reliability. This includes having top class lubrication management practices.
This level of quality workmanship requires high skills and use of testing and monitoring equipment. It will also require a re-write of both the maintenance procedures and operating procedures to include the specific actions that need to be done to get the engineering precision that ensures least stress in operating parts.
6. Make the Required Replacement Parts
Another potential strategy for securing replacement spare parts is to get them made and machined yourselves. You can use the original part in the equipment as the model to copy. With a metallic part, a metallurgist can assay the metal used for construction. The part can be measured to get dimensions. With that information the material for the part can be selected, and the item made in a machine shop.
If you can access 3D additive manufacturing, then 3D imaging can be used to measure the old part. Its dimensional details are put into 3D metal printer to fabricate the blank to be machined into the component.
7. Comprehensive Component Risk Elimination and Life Extension Strategies
We use a methodology called Reliability Growth Cause Analysis (RGCA) to identify the ways a component’s microstructure can be failed. Knowing what physics-of-failure events can damage a part’s materials-of-construction lets you identify situations and scenarios where those events can happen to your equipment. You then proactively design and implement risk elimination and risk prevention strategies to control/remove the chance of such events occurring in your operation.
If you see value in doing an RGCA to help spot and pre-emptively remove risks to your equipment, then start with a list of the parts in your equipment that you are concerned about failing during service. Put each component through an RGCA to get a wide range of effective component risk elimination and life extension strategies. The RGCA technique, with description and an example, is explained in the Industrial and Manufacturing Wellness book.
All the best to you,
Plant Wellness Way EAM System-of-Reliability
19 September 2022