The Höft & Wessel Group is a 400-strong, Hanover, Germany based manufacturer of ticketing systems, data collection systems and parking ticket machines. In a bid to optimise its processes and reduce wastage, the company has installed a simple data collection system from WERMA Signaltechnik, which is deployed as a wireless 'call-for action' system to tackle issues such as line material shortages as well as providing a complete overview of shopfloor activity. Erhan Kaya, Höft & Wessel's logistics manager, takes up the story:
“An optimised material flow without shortages or excess supply of material was the object of this exercise. Wastage, poor communication, errors and rework needed to be reduced to a minimum. Our staff had been experiencing difficulties estimating the work flow at any one station which led to over- and under-delivery of work and materials.”
Originally the company was looking for a visual display system to indicate the capacity utilisation of workstations and ensure better control of material flow. However, the company was attracted by the simplicity of WERMA's WIN (Wireless Information Network) system and since its installation the workflow at its Hanover plant has become much more transparent. Now, with a complete overview of the process available to staff, work flow has not only improved “dramatically”, but WIN has also helped Höft & Wessel to reduce process times and eliminate wastage from its service and repair operations.
The signal tower as an interface
WIN is a low cost, easy-to-install wireless based system that can be easily deployed to monitor and optimise machinery and equipment efficiency as well as workstation operations. A WERMA signal tower provides the basic interface; a transmitter (or 'slave') is easily fitted into the body of the signal tower, achieving both electrical and mechanical connections in a matter of seconds.
The WIN slave transmitter sends status change information to a receiver - the WIN 'master' - which is connected via a USB port to a PC. An unlimited number of clients in the organisation can view the data collected and displayed on the system. Höft & Wessel, for example, has installed this equipment on several workstations, and uses WIN in its service and repair centre.
Information concerning the workflow status is transmitted via WIN, and if a repair is finished a signal is sent to logistics. The logistics staff member uses the pull principle to supply the required material to the service centre. In this way the ‘first-in-first-out’ principle is upheld and material flow optimised. The repair cells determine the rate of work and demand new repair jobs according to their available capacity. Using this methodology Höft& Wessel can evaluate productivity, secure the process and save time.
WIN installation is very simple and no expert knowledge of software or programming is required. This was a key selection criterion for Erhan Kaya, who readily recommends WIN as a lean process improvement tool to any operator. While some employees may have viewed the installation of signal towers with some scepticism at the beginning of the project, Kaya confirms that nobody working on the production lines now wants to be without them.
WIN has functions other than that of a workstation call for action system. It can also be deployed as a machine data collection system (MDC). In larger machine shops where there are many machine tools or pieces of equipment, WIN is often installed to provide rapid detection of machine breakdowns or disruption to production. With the WIN slave permanently powered up, machine status changes can be collected in real time, giving the operator an instantaneous overview of machine shop activity and efficiency.
As a lean production tool WIN not helps reduce wastage and improve productivity; deployed effectively, it can also be utilised as a tool for improving product quality, inventory positions and delivery performance.
A WIN-win situation
The example illustrated here clearly shows how a simple system can make a significant improvement to processes, improve use of resources and reduce costs. This has been the experience of Höft & Wessel who has been able to improve its competitive edge and react quickly to changing market trends - a true WIN-win situation for both the company and its supplier, WERMA.