Management of Repairs/Overhauls

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Return to Process Pumps

Northparkes use work orders to identify what spares and materials are booked out on repairs/overhauls. Suppliers are linked into the CMMS and use the system. Tracking repair costs requires that discipline is used to record all cost to the work order.

Newcrest use OEM’s such as Westrack and Atlas Copco to carry out the majority of Rotable overhauls and have had a very good experience with this. The repair/overhaul report supplied by Westrack is high quality and is supplied electronically.

Sydney Water has not had such a positive experience with OEM repair/overhauls. As they do some in-house as well as outsource some overhauls they can compare and have found that OEM’s are more expensive. Sydney Water did have QA Inspectors that visited repair/overhaul suppliers. Since they have been eliminated there has developed a significant variation in the standard of repair/overhauls. There is an opportunity to better promote to management the benefits of reliability improvement opportunities such as better rotable management.

BOC perform many of the repair/overhauls in-house and has a rotating equipment specialist that has responsibility for this process. Typically OEM parts are used but due to cost and availability some parts are made locally with occasional reliability problems occurring.

When Qenos out-sources overhauls they include a repair specification. There are QA test specified on some items. Specifications are generic to specific equipment types. Some overhauls are strip and inspect to define the repair scope while other are just overhauls to a specification. In-house repairs are carried out as well but are generally not full overhauls. There is typically not a good repair history available for items.

Orica carries out overhaul of pumps in-house and has a reliability improvement program. For example oil seals have been converted to Viton to improve life. Orica has a good modification/change control system to help manage these changes. Orica uses inspection and test plans to manage QA issues especially for repairs associated with major outages.

The Bluescope attendees to the meeting where from the central procurement section. The steelworks have a huge range of rotable items from small gearboxes to $1M turbines. Most repair/overhauls are carried out by a core group of suppliers mostly from the Wollongong, Sydney and Newcastle areas. Recent had a major change in systems from SAP R2 to R3 and are still getting used to the new system. Most items go through a Strip & Inspect process and even if the item is to be scrapped it is always returned to site. It is found more efficient to have the central procurement group go to visit the external suppliers rather than all the local maintenance personnel attempting to see visit the suppliers.

OneSteel used to give repair/overhaul suppliers repair procedures. Now it tries to give repair specifications focusing on the required condition of the item on return. Have a specification for pump overhauls. Whether an item goes through a Strip & Inspect or just goes for an overhaul is determined case by case. OneSteel have a number of preferred vendors so that relationships can be built up and the suppliers learn what is expected.

The attendee from RTCA (Rio Tinto Coal Australia) was from a recently formed a dedicated group that now has the responsibility for management of QA for repair/overhaul of equipment from outside suppliers. This approach is used as local maintenance personnel who are responsible for the rotables have not got the time to visit the service providers or develop repair/overhauls specifications. The approach being used comes from a practice that was developed by Rio Tinto in Western Australia over a number of years. The approach focuses of having repair/overhaul specifications that determine the required condition that the item must be returned in. The group has written a few specifications so far including a generic repair/overhaul specification. Specifications should include QA measurement such as bearing housing ovality measurements defined in data sheets and included in the specification (often suppliers have there own forms). Building these specifications requires significant input from a number of different sources. Specifications are generic to equipment types with appendix to cover non generic issues. The experience is that good repair/overhaul management is a significant reliability improvement opportunity. They can help eliminate equipment standard failure modes by building better relationship with the vendors and collecting their detailed observation data that can help identify problems and improvement opportunities. The approach also allows building proper business cases for improvement effort/expense.

Hunter Water has many in-service pumps and all overhauls are out-sourced, about 90% of which goes to one service provider. The maintenance history for the pump repairs and overhaul has not been well maintained. There are some good SCADA systems that allow collection of equipment starts and run hours. The attendee from Hunter Water previously worked as an engineering supervisor for a repair/overhaul workshop. It was not typical to be given a good overhaul specification and usually had to probe customers to determine what the repair/overhaul requirement was. These activities are a significant opportunity for RCA of equipment problems.

Newcrest uses the rule that a repair/overhaul is carried out if the cost is less than 70% of a new items. Newcrest have their personnel visit repair/overhaul suppliers to view and discuss work in progress, even if that requires long distance travel. Repair/overhaul suppliers are encouraged to assist with reliability improvements. An example is special submerged arc hard facing zones implemented to improve wear resistance.

There is a significant choice between replacing an equipment items rather than doing a repair /overhaul. There is usually a lot more choice between supplier and equipment specification if an item is being replaced. Sometime the choice is driven by the urgency of supply delivery time requirement. It may be quicker to buy a replacement rotable if it is an off the shelf item. In other situations buying a new replacement has a long delivery time and a repair/overhaul, no matter how expensive, is the only viable option. In some situations a replacement items tends to have a higher reliability but if various failure modes have been eliminated or minimised a repair/overhauled item may have higher reliability.

A common theme was the requirement to limit the number of repair/overhaul suppliers for specific types of equipment. The supplier can then build their experience on this type of equipment and build a better understanding of the customers requirements. They can also have a significant input into building of the repair/overhaul specifications. Were there is a need for specialised measurement, QA testing systems and/or engineering resources, a service provider that has a regular supply of work can better justify this investment. Building personal relationships with the repair/overhaul supplier allows easier communication of requirements and generates more ownership of repair/overhaul quality issues and ensures the delivered item is more likely to be fit for purpose. The comment was made that vendor workshop personnel often love to have someone call in to discuss issues with work in process.

A key issue for management of rotable items is getting useful Strip & Inspect and overhaul reports from vendors. The ideal is to get electronic information including photos that can be stored as equipment history. The specification given to the suppliers should give the expectations for reporting requirements. The performance of a particular repair/overhaul supplier is often determined by the particular people and culture of the site. High staff turnover at the repairer’s workshop can be a cause of concern. An example was given of the higher quality of reporting from the Wollongong David Brown gearbox workshop compared to their Newcastle workshop. The detail that is reported should include breakdowns of cost, quantity of parts used, machining costs and labour use for verification of cost effectiveness and for future comparisons. The more detail given on quotes and reports the more transparency and trust there is that you are not getting ripped off. With a history of this information it allows benchmarking. Some suppliers don’t want to give these details but those who will, make better suppliers and are more likely to achieve efficiency and quality improvement over time. This type of data allows you to measure and control variation.

It was suggested that were Strip & Inspect work is carried out it tends to be easier to get the same supplier to do the repair/overhaul work. RTCA uses a system of getting three quotes from the strip and inspect report. A few of the larger organisations such as OneSteel and Sydney Water had some internal workshop resources. The major advantage of an internal workshop is that it is easier to coordinate and prioritise activities and also easier to carry out RCA investigations with building relationships with workshop personnel easier. You can also compare internal and external costs for similar or identical items. Sydney Water has noted when it started to outsource a significant percentage of its overhauls that cost went up $1,000 per item, which has now progressed to $3,000 extra. OneSteel often supplies parts for out-sourced repairs/overhauls rather than pay significantly higher mark-up rates from suppliers.

QA of repairs and overhauls was discussed. The worst case scenario was suggested that a supplier water blasts and paints an item such as a hydraulic valve and return as repaired. The ideal is that the supplier performs Condition Monitoring or Performance Testing before an item is returned. Sydney Water indicated that they get tank test carried out on overhauled pumps to verify there condition.

There were a number of comments around the need for good change control systems that are timely and not too onerous. They must ensure that shopfloor ideas can be encouraged and implemented in an effective way. Document management was considered to be important and also to ensure that any modifications go through the required change control process and changes are updated on the drawings. It is important that workshops don’t retain and reuse old drawings where there is a chance that they have been updated making the old drawing outdated. It was suggested that new drawings should be sent out with orders.

There was discussion around the role of central and local reliability engineers who have responsibility for setting priorities for improvement effort that includes setting standards and specification for off-line repairs/overhauls, associated QA, transport requirement and storage requirements. This role has the need for high quality maintenance equipment history data to be collected with good data on spares and rotables to help with inventory level decisions. Better inventory management was considered a significant opportunity.

One of the issues with management of rotables is the number of separate groups that can be involved in the repair/overhaul process. Typical groups would be maintenance planning, site maintenance crews, supply/procurement organisations, transport companies, repair service providers and stores organisations. The rolls and responsibility of theses groups related to rotables can vary. Also there is the likelihood of Silo effects with its limiting effect on communication and cooperation that have to be countered.