Providing precision components for the global aero-engine market, Accrofab Limited is a key link within the aerospace industry’s supply chain. The company depends on Jobshop software, from Planit, for the control of up to 1500 current parts as well as an ever-growing list of legacy components for older engines.
Located in a purpose-built 31,000 ft2 facility in Spondon, Derby, Accrofab was originally established in 1977 to support the rail industry. However, the company quickly moved into aerospace sector and now employs 92 people. Today the company’s core business is aero-engine parts with a Derby-based aero engine manufacturer being a major customer due to the location and skill sets offered by Accrofab. These include small fabrication and precision machined parts up to 300 or 400 mm3, as well as components that have elements of these two disparate disciplines included. Materials processed include stainless steel, titanium, Inconel and nimonics.
The business started with fabrications and the precision machining section grew to support the fabrication tooling requirements. However, as engines have become more advanced customers required increasingly complex fabricated parts, and many of these now have features that require machining or precision machined elements to be included. Manufacturing manager, Ed Ashworth, explains: “As a company we have a broad range of engineering skills, these include fabrication, machining, laser cutting, welding, heat treatment, spot welding, spark and wire erosion, brazing, and bonding. We hold aerospace customer approvals for all these processes.”
Accrofab has used Jobshop for more than 15 years and has grown with the system. As the company expanded the software was networked and very quickly became central to the manufacturing business. “Apart from the accounts and wages it runs everything in the business, everything is done through Jobshop,” says Ed Ashworth. “With experience we have used more and more of the features of Jobshop as they have developed. And, because of our specific customer requirements one of the benefits for us has been the customisation that Jobshop can offer through bespoke modifications undertaken to meet our customer needs.”
This ranges from simple things like packaging and labelling up to bar code data being used in processes on the shopfloor to drive the equipment rather than relying on operators rekeying data. He says: “We face all sorts of customer specific requirements for inspection and we are using the First Article Inspection Report (FAIR) procedure that Jobshop developed for us within the software.”
Ed Ashworth continues: “FAIR has to be done every two years if there has been a gap in manufacture. The software flags any parts that require this procedure automatically and ensures that we send the appropriate documentation when the parts are dispatched. This removes the possibility of human error.
“About 18 months ago we began an improvement initiative within our finished parts stores. We were running out of space within our traditional stores area, which had parts in plastic storage bins on racked shelves. Smaller parts were placed in shared boxes and because everything we make is fully batch-traceable we had to ensure that the components gathered for assembly or for kits, supplied directly to the customer via a kanban system, were selected from the correct manufacturing batch to maintain traceability.”
Parts are produced in economical batch sizes to suit the customer’s order profiles. Batch sizes range from one off up to 1000 parts although 20 to 30 is more typical. The finished components are then stored until required for the kitting operation. A kit of parts may have up to 50 individual items included in it, and reducing the time spent picking parts is crucial. “So our main goals were to increase the storage capacity, minimise the storage area used and improve our pick times,” Ed Ashworth says.
Accrofab investigated various solutions to its storage problem and holding parts in a vertical carousel system proved to be the most efficient and effective. “We had seen the systems in operation in other companies,” Ed Ashworth recalls, “but assumed it would be an expensive option. In reality the investment was not as significant as we thought it would be.”
Although the storage tower was the obvious solution it was essential that it would work with Jobshop to provide the level of control the company demands. It was interfaced very successfully as Ed Ashworth confirms: “As we book parts through inspection and into the stores Jobshop prints out a bar code ticket which contains information on the part number, batch number and quantity and then by simply reading the bar code labels we load them into the storage tower.”
With up to 4000 random locations, the parts can be placed in any location within the tower providing it fits inside one of the six standard bin sizes. This avoids having empty bins waiting for discrete items and removes any possibility of mixing the manufacturing batches up.
Once a part is loaded into the tower its control system has a stock record with a storage location. Ed Ashworth says: “When it is time to retrieve the parts we simply book them out using Jobshop in the normal manner this creates a CSV file which is sent straight into the tower’s SQL database. As we produce a delivery note Jobshop produces a bar code which is printed on the top corner of the delivery note, which when read by the tower will automatically rotate around to present the job that needs to be dispatched to the customer. It removes the need to search in various tote bins as the stores person is directed straight to the correct part from the right batch, which has to be verified in the tower software so the customer is guaranteed to get the right part.”
With around 1500 live part numbers going through the shopfloor that can be called upon at any time by its customers, component control is vital to the company’s AS9100 quality control procedures. “Jobshop knows what is held in the tower as well as what work in progress is held on the shopfloor, with shopfloor data collection providing a real-time update on where any part is at any time - again using bar code technology,” concludes Ed Ashworth.
The aerospace industry represents a majority of the company’s workload; however Accrofab also provides commercial fabrication, machining and laser cutting services to local engineering firms. Laser cutting is operated as a business cell that acts as a profit centre, the company’s new 5 kW Trumpf laser was added in April 2007 to supplement an existing 3 kW Trumpf machine. Able to handle sheets up to 3000 by 1500 mm the 5 kW laser resonator was chosen to efficiently deal with the broad mix of materials that the company has to cut as a commercial operation.