"Our customers are the central focus, no matter if they only order one single item or a series of 1000 or 3000 parts", Ralf Beitlich, Head of Logistics Department at Otto Ganter GmbH & Co. KG in Furtwangen, Germany, points out. His company makes high demands on logistics operations, "We guarantee a delivery availability of 98 percent" – which is a high-level commitment in view of the large range of SKU and product diversity.
Ganter, a medium-sized family owned enterprise with more than 220 employees, is a leading provider of standard parts, offering an extremely vast range of clamping, locking and machinery elements as well as industrial components, articles for medical and rehabilitation engineering, food engineering and the wood-working industry, agricultural machinery and kitchen equipment. Another ever growing sector are stainless steel products.
98 percent delivery reliability makes high demands on material handling
By now, Ganter is stockpiling about 30,000 different parts at their plant and distribution centre. In order to adhere to the guaranteed delivery availability for 24-hour delivery service within Germany and 48-hour delivery service in Europe for this large range of items, Ganter needs all systems and processes to be absolutely reliable and available.
Therefore, the company did and does not take any risks when it comes to its warehouse and material handling equipment including controls and, despite of periodic maintenance and proven long service life of the systems used, decided to modernise the 11-year-old tray warehouse and connected conveyor loop at the right time. Ganter has been relying on equipment and system performances of the TGW Group for 11 years.
Tray and tote warehouse as logistics "motors"
Two extensive storage systems, a tray and a tote handling system, are the key elements of the material handling system. The four-aisle tray warehouse planned in 1999 and implemented in 2000 accommodates 16,000 storage locations and is serviced by four TGW Stratus automatic storage and retrieval (AS/R) machines.
The trays with dimensions of 1350 x 555 mm, heights ranging from 150 to 330 mm and a load capacity of 200 kg, can be subdivided into up to 18 sectors, depending on the respective item to be stored. The tray warehouse provides a maximum performance of 140 double cycles per hour, which Ganter will be benefiting from to the fullest after the conveyor loop will have gone through retrofitting, too.
The fully automated tote warehouse put into operation in 2008 was planned and implemented by TGW in close collaboration with Ganter, too, as a response to the positive business development and high demands on the afore-mentioned delivery availability. The warehouse has four aisles that are operated by TGW Mustang cranes.
Retrofitting of tray warehouse and conveyor loop including migration from S5 to S7 controls
Looking at the logistics functions of the two storage systems makes the reasons for modernisation clear: With a storage volume of about 3,000 cubic metres (3,900 cubic yards) and high payload capacity, the tray storage system serves as buffer warehouse stocking up all incoming goods, both finished and semi-finished products.
But it turned out that an efficient interplay with the tote warehouse and the resulting uninterruptible workflow was no longer satisfactory, as the tray warehouse had become too slow.
The high performance tote warehouse accommodates 35,000 VDA standard totes with a dimension of 600 x 400 mm and a load capacity of up to 50 kg in a double depth structure and performs a maximum of 480 double cycles per hour.
Ganter classifies the products according to the ABC principle in "fast-movers", medium-movers" and "slow-movers", the categorisation being calculated by the WMS on the basis of the access frequency to the items. Fast- and medium-moving items are stocked in the tote warehouse with an average stocking period of 25 days plus 5 days of reserve, as a daily stock rotation would not make any sense. Slow-moving items, which make for the largest quantities, are stored in the tray warehouse.
Retrofit Task Force has access to entire expert know-how of TGW Group
The first important reason for retrofitting the tray warehouse was the controls update from S5 to S7. The AS/R machines were completely modernised. And as TGW is servicing the storage systems anyway for 4 days every 6 months, Ganter entrusted the Austrian specialists with the controls update to S7 as well as the complete modernisation of the AS/R machines and the conveyor loop. The latter assumes storage and retrieval functions in the AS/RS approach zone and supplies the four picking stations on the ground level of the distribution centre with items and parts.
Whereas the number of handling cycles in the tote warehouse could be increased by an additional AS/R machine, as Ralf Beitlich explains, "the timing chain conveyor system is the time-determining factor in the tray warehouse".
Only 3 days available for each AS/RS aisle retrofit - including controls update
The first tray warehouse aisle was modernised beginning of May 2010. Apart from precision and reliability, quickness is the key to success, "We are able to revitalise a complete AS/RS aisle within three days", says Werner Weißböck, Sales Manager Retrofit at TGW Systems Integration in Wels, where a team of 25 specialists is available for retrofit. His task force, Werner Weißböck points out, consists of "highly qualified controls, IT and mechanical engineering experts who draw on manpower from the company group and have online access to the whole TGW know-how any place and time via data communication."
"Our biggest challenge at Ganter was that we could only use a time slot between Thursday evening, 6.00 pm, and Monday morning, 6.00 am", as one of the customer's requirement was to guarantee no disruption to warehouse operations. In this extremely short period of time the complete TGW retrofit team worked on site in two to three shifts. In comparison, the start-up phase normally requires the on-site presence of 1 to 2 engineers only, additional employees being ready to be called off to the site from Wels, and online support being available 24/7 anyway.
Pre-assembly and completeness checks of components in TGW Test Centre saves important time
Such extremely tight time frames for retrofitting can only be observed thanks to TGW's in-house Test Centre. All AS/RS components to be replaced during the Ganter retrofit project, such as load handling devices and drives, were pre-assembled in the TGW Test Centre in Wels as well as thoroughly tested and checked for correct functioning. This considerably saves time on site and increases the components' operating reliability, as Werner Weißböck explains, "Commissioning and testing the controls and mechanical components in advance in our Test Centre helps us to save valuable time, as we do not need to retrofit the mechanical equipment and carry out function tests on site, but are able to install ready-to-use components and modules".
The control cabinets for the S7 control system, that are considerably smaller than the ones used before, were pre-assembled and tested in advance, too. Afterwards they were mounted onto the masts that had been reduced to the "chassis" and steel framework before.
TGW equipped the four AS/RS machines with new load handling devices, drives, running and guide wheels as well as new cable carriers of the latest generation, reinvigorating the technology for the future.
Innovative TGW Online Service concept: "any place, any time"
The new S7 control system offers direct dial-in via Internet, which improves and facilitates the installation, maintenance and retrofit: "Our concept is called "any place, any time", says Weißböck. "This means that any of our authorised employees is able to access our customers' installations online from any place in the world. If there is a problem in an installation that can only be solved by a certain TGW specialist who is currently working on another project, this specialist will be able to log on to the customer site via a special online account. This procedure provides enormous time and economic advantages".
Ralf Beitlich is very satisfied when recalling the recent retrofitting work: "I was enthusiastic about TGW's approach right from the beginning: The removal of the old and installation of the new AS/RS components was done in a very coordinated and fast way, starting work at Thursday evening. On Friday evening, the first controls engineers were working on site already".
To be on the safe side, TGW brought all components that were required for commissioning, such as controllers and motors, with them in duplicate, in order to lose no time whatsoever in case of need.
After the first controls update, the TGW retrofit team was on site for a whole week
Operational safety always comes first: "During the week after updating the controls of the first AS/RS aisle, TGW was on site for "production support", in order to be able to take corrective action immediately in case of problems".
After one to two weeks of normal operation - in case of Ganter with one modernised and three "status-quo AS/R machines" - the second aisle was updated, then the last two. The whole updating and retrofitting process extended over a "period of 8 to 10 weeks, in which only four weekends were relevant for the customer", says Weißböck.
The retrofit project will be completed end of this year, when the existing S5 control system of the conveyor loop will be replaced by a S7 system. The mechanical equipment of the timing chain conveyor only needs minor modernisation, only the Interbus lines will be replaced by ProfiBus technology.
Trustful cooperation partnership for many years
Needless to say, Ganter's shipping operations still work excellently and, after retrofitting, more effectively than ever: Between 2,500 and 3,000 order lines are picked for 600 to 700 order consignments per day, shipped on about 20 pallets, 40 percent of which being delivered across Germany and 60 percent worldwide.
Ralf Beitlich is very satisfied with TGW's performance, "TGW is advising and serving us with the best possible methods, technologies and tools, we feel that we are in good hands".
The customer's satisfaction is proven by the long-lasting cooperation between Ganter and TGW since 1999 and the service contracts that Ganter closed with TGW for both storage systems, "TGW's service concept and their philosophy of detecting defects in due time and provide preventive maintenance measures always served us well".