Like a computer hard disk: Intelligent material buffers increases the competitiveness

Fast internal logistic chains are fundamental components when it comes to increasing the productivity of a manufacturing company. The trouble-free material flow especially plays a main role in the permanent endeavours to optimize costs when it comes to turning serial elements into customized ex works solutions.

One example of the switching from serial production to the customized manufacturing is sandwich elements for sectional doors. The sections are manufactured in a continuous production process on an approx. 100 metre long production plant – referred to as a Kontilinie. The sandwich-designed sections comprise two hot dip galvanized steel sheets as an outer skin. The two sides are connected by PU foam, thereby providing stability and the insulation of the building at a later date.
Different gate lengths and widths in combination with different thicknesses, colours and surface structures results in a compromise being found between a costs-optimized production and the fast installation of doors in a batch size of one. The clients also expect short delivery periods after the order has been placed. With this in mind, Falk Steuerungssysteme GmbH has established an internal high bay warehouse for the town of Stadthagen in Lower Saxony. The fully automatic picking of individual sections or stacks is hereby carried out by a storage and retrieval machine in this warehouse. The warehouse has been designed as a material buffer for the finished orders from the Kontilinie line. Flexibility was right at the top of the list of requirements during the planning stage. This is why the different sections with their various lengths and widths do not have certain storage bays allocated to them. This renders the intralogistic extremely flexible, but also results in complex visualization and controlling structures. The warehouse is also subject to direct SAP access in addition to it being firmly implemented in the location control level.




"The virtual warehouse thinks in future terms and creates the possibility of calculating picking processes in advance", is what pleases Alexander Jung a software developer at Falk.

The warehouse thinks in future terms.

The different stacks of sections are therefore presented in the warehouse visualization in the form of coloured clusters. "This enables various lengths to be visualized very easily", explained Alexander Jung, a software developer at Falk. The conception went to such an extent that the storage jobs were initially simulated. "The virtual warehouse thinks in future terms and creates the possibility of calculating picking processes in advance." The aim here is to initially determine whether storage is possible at all and that before the storage and retrieval machine has received the corresponding travel commands. Falk has also developed a piece of animation software for the virtual warehouse so that it will be possible to quickly recognise the logistic processes which will take place at a later date. It displays the current occupancy of the warehouse and the movements of the storage and retrieval machine which has been designed by Falk. The idea behind this sophisticated system lies in the nature of a sectional door. They are normally individually installed, depending on the length and height. Whilst the cross cutter automatically specifies the section length at the end of the Kontilinie line from the job order, the later door size is determined by a combination of various section heights. These cannot however be manufactured simultaneously in a continuous production process, but when taking expensive retrofitting times into account, they are to be combined from various production batches. This results in an intermediate storage and an job-related picking.



Intermediate storage of finished sections in the internal high bay warehouse.

Keeping up with the production

The employees enter the items which the storage and retrieval machine store and retrieve in the high bay warehouse into the control system. The production orders are also controlled from here, either by them being directly input or from the SAP system. "Optimizing processes means that the warehouse system itself has to work efficiently and fast so as to keep up with the production", explained Martin Falk, Managing Director of Falk Steuerungssysteme.
The experts have designed the warehouse so that orders from the production can be placed in the immediate vicinity of the storage station. The consequence for the storage and retrieval machine is short distances and therefore save time. The reverse conclusion would however be that the retrieval at the other end of the warehouse would take all the more longer.



A cooling section receives the sections which have been precisely cut to length.

The solution

The system defragments itself like a computer hard disk.
If no storage or retrieval is taking place, the storage and retrieval machine transfers pending jobs, closes gaps and thereby also makes space in the storage area. Picked stacks finally leave the warehouse. With its suction cross-member, the storage and retrieval machine is also able to remove individual sections from the storage bays in addition to it providing all of the sections which are required for an ordered door as a stack so that it can be processed further and assembled. During the storage of production orders, consideration should already be given to how the individual sections can be quickly retrieved from the warehouse later. The retrieval of the sections from storage for further processing on the assembly line is normally carried out via a bridge which in turn represents a material buffer. Typical processes here are the job-related sawing, drilling, painting or stamping. This work is also fully automated. Hereby, each of the components is to be clearly traced in the visualization in addition to it being an inherent part of the continuous data management. An operator can call up the entire data set with a click of the mouse, including the production number form the ERP system. Those who look back at the times before the intelligent warehouse will see extensive external storage facilities which acted as a buffer. Employees had to search for the required parts in what was often a time-consuming manner, before putting them together mechanically. An additional disadvantage: the elements were subject to weathering so that there was a large proportion of scrap. Nowadays, the internal high bay warehouse is an example of how sandwich elements can be more efficiently and therefore less expensively produced by means of a polished intralogistic and purposeful production. It all comes down to increasing the competitiveness in an international market.



The system is so designed that the storage and retrieval machine only has to travel short distances.

The author Thorsten Sienk is a freelance specialized journalist from Bodenwerder.


Retrieval of sandwich elements via a bridge for further processing.