Maintenance fear factor
6 Feb 2012
The importance of effective sourcing and management of spare parts is often ignored at many process operations, to the detriment of continuity of production as well downtime and inventory costs. The shortcoming typically stems from outdated attitudes and practices in the maintenance department - which could, however, be set to change.
“Years ago, people would come in fill the shelves with parts, and you’d get a bill at the end of the month,” said Rick Littlefield, business lead for the contracts side of Rockwell Automation’s service business. “Today, customers, who are carrying parts worth several hundred thousands of dollars in there, are saying ’wait a minute why are we doing this?’”
The biggest reason is a fear of not having spares in stock, ” according to Littlefield. “For electrical engineers, for example, the no 1 goal is to keep machines up and running. So they hoard the pieces and parts in case the store room doesn’t carry them. That’s not a good maintenance strategy.”
The no. 1 goal for engineers is to keep machines up and running. So they hoard many pieces and parts in case the store room doesn’t carry them
Brynn Woods, purchasing & distribution director of Brammer UK, emphasises the financial downside, noting that spares stock purchased ’just in case’ often becomes non-moving stock, tying up cash at the time of purchase. Many parts, he adds, ultimately becoming obsolete and are written off on the balance sheet.
Woods’ mantra for successful spares management is ’low inventory - high availability’. This, he said, is especially important in larger manufacturing operations, where the list of SKUs (stock-keeping units) required for plant maintenance operations can run into thousands.
“Not only are the required spares often of low value and required infrequently, but the sheer range of components the engineering team need to have access to can be daunting, meaning dealing with multiple suppliers and a consequent lack of purchasing leverage,” said Woods.
“Meanwhile the technical complexity of the spares and erratic demand patterns - only around a third of spares consumption repeats in consecutive years - can also be problematic.”
According to Woods, best practice in this area is for inventory to be routinely profiled to ensure accuracy and alignment with consumption of key components. There should also be a focus on standardisation of key products and technologies throughout the plant.
“Identifying which machines require the same spares - even across different sites - and then sourcing these from a single supplier, can radically reduce stockholding and working capital, ” said Woods. “A detailed review of what components are being sourced and from where, will highlight areas of duplication and allow the supplier list to be radically trimmed.”
This can mean getting rid of many thousands of dollars worth of parts that people are stashing in these little compartments, thinking they might need them some day
For his part, Littlefield at Rockwell advises: “Leaning out that inventory and changing processes to shorten the time it takes for a spare part to get from inventory to the machine - and so reduce downtime and overall maintenance costs.”
This can mean employing designs and systems that, for example, ensure that the most used items are to the front, and refining processes for receiving, putting goods on the shelves and accurately accounting for and tracking them. Inventory strategies can encompass linking costs to individual machines, product quality and maintenance regimes.
According to Littlefield, managers should ask questions such as: Are we buying top quality parts or does it make sense to repair, or if we can get a product at a better price, is it necessarily the right product? Why are we going through so many of them?
“One of the things we improve at our customers is around defining the maintenance strategy and guiding reinvestment in inventory to make sure they have the right stuff that matches the demand on the plant floor.
“This can mean getting rid of the many thousands of dollars worth of parts that people are stashing in these little compartments, thinking that they might need it some day.”
Mobile link for chemicals production and logistics
Construction chemicals manufacturer Lugato has noted significant gains in efficiency through using a software application that extends continuous monitoring of its operating activities onto mobile devices.
Lugato, which manufactures tile adhesives, speciality paints and filler compounds, is using a mobile SCADA application, from Schad Ltd, on the production lines and automated materials handling systems at its Hamburg and Barsbüttel facilities in Germany.
Lugato’s production and logistics operations had previously been run as separate functions, resulting in relatively high overheads. In the event of plant malfunctions, notifications and alarms were only sent to the control room by telephone, so that two engineers would always be required to attend to a problem - one situated at the failure point and one based permanently in the control room.
Activities across the two divisions have now been merged onto a single user interface - a standard BlackBerry smartphone. Technical engineers receive real-time notifications of system performance issues if a problem occurs anywhere within the facility directly onto their mobile devices, which have been converted into automated systems controllers.
Schad’s system uses existing Wi-Fi or GPRS infrastructure, which it claims provides a low-cost mobile control and monitoring solution.
The software works by granting secure remote access to Lugato’s automated systems and so allow system controls to be constantly monitored.
Depending on their authorisation level, engineers can gain remote access to control systems to investigate system performance problems on the spot, or check for parts availability. They can also access multiple control and maintenance systems from a single user interface on standard mobile devices.
Prior to adopting this technology, information relating to the continuous smooth running of the warehouse was displayed visually in a dedicated control room. This was staffed by warehouse engineers, who monitored the automated systems.
Acting as an unmanned control room, the Schad system keeps Lugato’s employees informed 24/7 about technical failures and the critical states of each automated process, on their mobile devices. Downtime has been reduced as engineers can access information about problems directly from any location, without having to report to the control room.
Information required to remedy a fault - including all job processing data - is also instantly available to all employees, regardless of where they are located - again, without the need to rely on other people in the control room. The system creates an automatic work flow, keeping everyone informed of issues and their outcomes.
Since the implementation of the system, the need for time-consuming job allocation of on-site personnel by the control room, either by phone or radio, has been eliminated, Lugato also noted. Distances travelled by each employee within its large industrial complexes also reduced, allowing them to focus more on core maintenance tasks.
Overall, Lugato estimates that the mobile SCADA technology has improved its machine availability levels and increased staff efficiency by around 3%.
The system has also reduced downtime by around 30 minutes a day, the German chemicals maker estimates. This extra half an hour of machine availability has enabled it ship an extra truckload of finished products a day.
