Running a world class international distribution business requires the very best management information systems, but keeping the software updated without service disruption is a significant challenge RS Components found a very effective solution when it needed to prepare its warehouse automation systems for a new enterprise software implementation.
For people working in a diverse range of industries across the world, the first port of call when a requirement arises for a new or unusual tool or part is RS Components. Founded to supply spare parts for radios from a garage in London in 1937, RS has since expanded to include operations in 24 countries and exports to a further 160. It now supplies electrical and electronic components, industrial tools, parts and equipment, and a growing range of IT and health & safety related items. The company stocks 160,000 different product lines and makes these available by overnight delivery to over 1 million end-user customers world-wide.
Quality of service
We are not a wholesaler, explains John Wilson, Operations Manager at RS Components distribution centre in Corby, Northamptonshire. A majority of our customers come to us with relatively small orders, but most need them delivered the next day. For RS, quality of service is an absolutely vital business driver. Well pay a premium if we have to, in order to make sure that even a couple of small packages arrive with the customer on time.
Obviously, RS needs to make sure that this situation doesnt arise too often, which is why it relies on the very best automated handling systems, software and business processes to ensure that its hugely complex distribution operation works smoothly and efficiently, 24 hours a day.
As RS Components has expanded, so the logistical complexities involved in achieving this level of service have increased. The number of product lines stocked has doubled in the past ten years, and while increasingly sophisticated purchasing and stock management strategies have kept inventory levels under control, maintaining the required balance of product availability and speed of service is still a demanding process.
In the UK, RS has two major warehouses, at Corby where the 50,000 fastest moving lines are kept and a newer facility at Nuneaton in Warwickshire, which holds the remainder of its inventory. To meet its customers requirements, RS must ensure that all orders can be received, processed, picked, packed and dispatched in less than 2 hours. At Corby it must be able to do this for circa 9,500 separate customer orders every single day a total of some 30,000 order lines per day. As well as fulfilling customer orders directly, the two UK warehouses also provide stock for the companys 19 trade counters including call and collect facilities around the country and for all its subsidiary warehouses in Europe and Asia, an activity that takes place overnight, after the final UK customer orders have dispatched.
RS has designed its facilities to operate as a truly integrated, global business, as Brian Simpson, the companys facilities development manager explains. Our distribution centre in Italy, for example, has 31 picking faces, exactly the same number as here in Corby. When we have an order to restock the Italian facility we can load totes at the appropriate picking faces here, ship them to Italy and take them directly to the corresponding picking face there for restocking. It saves a tremendous amount of effort and improves accuracy, quality and service.
This search for truly world-class operations and processes led RS to examine its entire business software infrastructure, in a project known as EBS Enterprise Business Software. The decision was made at that time to replace a variety of existing systems with a single, modern platform that would provide a robust, scaleable and replicable basis for the companys future growth. RS selected SAP as the right product for the job and began the process of integrating it into its operations worldwide.
An SAP implementation is an activity that has repercussions at every level in an organisation, and the operations management at the Corby site were no exception to this rule. Corby has an automated handling system, designed and installed by Vanderlande Industries in 1984, which carries product totes between goods receiving and the high bay storage facility.They are then retrieved and routed to the picking faces for replenishment. A conveyor system routes picked order totes through the various zones. Completed orders are sent to a packing area prior to sortation for despatch. This network was originally controlled by a Conveyor Control System (CCS) which takes instructions from the warehouse management systems, makes decisions about how totes should be routed, and gives appropriate instructions to the PLCs controlling the conveyors on the warehouse floor.
The existing CCS was installed by Vanderlande Industries with the materials handling system in the 1980s, and has operated reliably since then, but when the SAP implementation process began, all of the software systems at RS came under review. When we looked at the CCS, we soon realised that it was simply unable to deliver what we needed in the new software environment, explains Wilson. The most cost effective thing to do was replace the system with a more modern alternative.
Vanderlande Industries had installed the original system and it was essential that the quality and reliability of the original system was duplicated in the new one. This is a business critical system and we were determined to ensure that the replacement was a best-in-class product. The ability to provide a comprehensive level of maintenance, support and training was vital in the new programme, explains Wilson. The loss of our warehouse automation systems, even for a short period of time, would have a catastrophic effect on our quality of service and on our business.
To ensure that it really was selecting a best-in-class solution, three automation specialists were invited to tender for the work in early 2002. RS carried out a formal comparison of the three systems on offer, and Vanderlande Industries was able to demonstrate quite clearly during this process that it not only had the technical capability to implement a system that matched the customers requirements, it also had the resources and expertise to support it and deliver the level of availability that was so vital for the component distributor.
Vanderlande Industries size and scale, the advanced nature of its Warehouse Control System (WCS), its intimate knowledge of warehouse automation technology, and its extensive experience of the mail-order sector, gained through numerous system integration projects for mail-order companies throughout the world, gave RS the confidence that of the three tendering companies Vanderlande Industries was the best choice for the WCS replacement project.
The decision to go with Vanderlande Industries was made in September 2002, system design was complete by May 2003 and the new WCS went live in July of the same year. To make the implementation process as smooth as possible, Vanderlande Industries used the proven project management process it has developed over numerous implementations of its systems with customers worldwide. The RS installation was far from a typical one, however. The new RS system had to be fitted into an existing, fully operational facility without modifying either the PLC hardware or the host system software and without causing disruption to existing operations.
The key to success in this demanding environment was teamwork. Vanderlande Industries and RS personnel worked closely together throughout the programme to ensure the best possible chance of success. While Vanderlande Industries had a lot of expertise and experience in the project management of software implementations like this one, we were able to bring our own project management experience to the process, explains Simpson. We have a lot of experience in the management of risk, which is very useful in a project like this.
Testing the software system and communication interfaces in a fully operating environment is a challenging process and the close partnership between Vanderlande Industries and RS helped this part of the project to run smoothly. While as much testing as possible was carried out off-line, the system had to be evaluated on the real hardware, and that meant running trials at weekends when the warehouse was not operational. To make the testing process as efficient as possible, RS and Vanderlande Industries combined their normal testing programmes into a single set of tests designed to ensure that both parties achieved their objectives in the most efficient way possible.
The entire Vanderlande Industries WCS system installed at RS Components in Corby is designed to maximise availability and minimise the possibility of service disruption. As part of the project, Vanderlande Industries has guaranteed the software to provide an overall availability level of 99.8 percent. To do this it makes use of multiple levels of redundancy. Communication from the control computers to the PLCs is carried out over a bespoke TCP/IP network, installed separately from the sites main IT network and configured so that there are at least two possible data paths to every device.
All WCS functions are controlled using redundant clusters of computers with shared redundant disc arrays. The computers are held in two separate computer rooms some 500m apart at opposite sides of the site. In the event of a failure in any first control computer, the second will immediately take over using the data stored on the common disc to ensure uninterrupted supply. Likewise in the event of a disc failure the operation switches seamlessly to another disc. The faulty drive can then be replaced whilst the system is still operational. In the unlikely event that the entire disc storage fails, a backup machine with a mirrored copy of the system database will immediately take over to reconfigure the system. This process takes around 30 minutes, during which time totes continue to circulate on the conveyor system. Once the WCS is back in operation it redirects the circulating totes to their appropriate destinations.
Logically, the WCS has been designed to fit precisely into RS Components IT infrastructure. Below the WCS are the existing PLCs, while above it at the time were two layers of software MQSeries Integrator from IBM, which handled network traffic and communications, ensuring that messages continued to reach their destinations regardless of changes in hardware configuration, and the Enterprise Applications Integrator (EAI) which handled the communication between the WCS and the warehouse management system.
The main priority for RS in implementing the new CCS was to ensure uninterrupted levels of service to its customers. If our customers noticed that anything had changed, we would have failed, explains Wilson. In practice the transfer to the new system was a seamless one. We switched over to the new system at the beginning of the week, and while we always had the option to revert to the old one that simply has not been necessary, he notes.
It may be business as usual for customers, but the implementation for the new system has brought a number of direct benefits for RS employees and management. At the time of implementation, 51 operator terminals were located in the system which now use a modern graphical user interface, based on Microsoft Windows technology, which is a lot friendlier than the old text-based consoles. This not only makes the operators jobs easier, improving picking accuracy, it also makes it much simpler for management to view and analyse the state of the system at any time.
Perhaps the most dramatic operational benefit has come about in the restocking process, however. Under the old system, operators involved in restocking used handheld scanners with barcode readers to track empty boxes and incoming stock. These readers needed to be docked with a base station periodically in order to download their data and ran using a separate database that was synchronised with the main stock control system on a batch basis. As part of the WCS system, Vanderlande Industries has integrated handheld scanners with a wireless connection directly to the main computer network. As totes are scanned in, the system updates in real time, once again maximising reliability and improving the depth and quality of stock information.
Ultimately, says Simpson, it was the ability of the Vanderlande Industries engineering and project management team to integrate successfully with the RS components personnel that made the WCS replacement project a success. There was a very positive, constructive atmosphere throughout the programme, he says. The Vanderlande Industries team was able to guide us through the implementation process in a rigorous manner, but they were flexible enough to accommodate our specific needs everyone was working together towards a common goal, which we achieved very successfully.
On completion of this phase of upgrade, RS Components Corby was still running on its legacy IBM mainframe system. The next phase saw the mainframe change to a SAP operating system again supported by Vanderlande Industries so ensuring that the WCS could continue to operate with the minimum of re-configuration.
And the story goes on
In 2005/2006 the complete Host interfacing changed from IBM mainframe system to a SAP ERP/WM solution. The interfacing between the SAP Host and the Vanderlande WCS VISION changed. As a certified SAP Partner with standardized and validated interface communication to SAP systems Vanderlande supports this re-engineering perfectly in time without any interruption of the distribution processes. One reason for this successful integration is the support of the VISION WCS with separated test systems and environments like the SAP development and implementation structure. Another success component is the great experience of Vanderlande Industries in system integration within a SAP IT landscape.
To complete the jigsaw
Vanderlande Industries have now been awarded the contract to completely upgrade the PLC hardware and software level of control, so completing the conversion of the entire RS Components Conveyor Control System without disruption to ongoing operations.
Warehouse Control Systems
The Warehouse Control Systems (WCS) manage and optimise the routing and balancing of totes in an automated handling system. A WCS receives instructions from the main host system about which pick faces need to be reached for a particular order. It then directs the tote through the system, monitoring its position using RFID tags and conveyor system photocells and issues appropriate instructions to the PLCs controlling the conveyor system itself.
The status and position of a tote is monitored and updated as the tote progresses through the system ensuring fast and accurate control.
A modern WCS like the Vanderlande Industries system VISION used at RS contains many features that make recovery from hardware failures straightforward and can be easily integrated with the rest of an organisations business software.