The German automotive supplier Hella develops and manufactures lighting technology and electronic components and systems for the automotive industry. With a turnover of 3.7 billion Euros the group ranks among the Top 50 automotive suppliers worldwide. More than 25,000 people are employed in 70 manufacturing plants, production subsidiaries and joint ventures in 18 countries.
Technology by Hella is included in virtually every single car. The company has recently centralised the entire logistics operations of its production site in Recklinghausen. The project was planned by Miebach Consulting, implemented by TGW and is now operated by Lila Logistik.
At the Recklinghausen site, Hella manufactures lighting and electronic components, sensors, actuators, x-by-wire systems as well as optical and acoustic signal systems in two production areas. Historically these two areas have been supplied with production components in a decentralised manner. This is also true of its distribution activity which was also organised and processed at several decentralised locations. The newly constructed logistics centre put into operation in October 2007 now accommodates both the production and distribution operations. The Lila Ligistik operational team has to deliver a high service level to complete material requests of the different workplaces within a maximum window of just one hour.
The logistics centre comprises several different storage areas. All “A” classification items are stored in a traditional pallet warehouse served by forklift trucks. These items are delivered and stored on pallets and on request transported to the different production areas via an in-floor conveyor system.
The “B” and “C” categorised items are stored in an automatic small-parts warehouse. Four storage aisles each 45 m long and 9 m high are equipped with the high-performance TGW automated storage and retrieval machines of the type Mustang. The four aisles accommodate 27,000 trays which act as storage shelves for the stock items which are received either in cartons or tote bins. The Mustangs retrieve up to 600 trays per hour from the warehouse to supply the items to the production work stations and dispatch area.
The automatic warehouse is located to one side of the logistics centre and is connected to the work station positions via the automated conveyor system. The pre-storage area and conveyor network are installed on a raised platform which frees up valuable ground floor space and maximises the use of the available headroom. Two TGW continuous vertical conveyors each delivering up to 800 trays per hour, connect this conveyor level with the working areas on the ground floor.
Core elements of the logistics centre are the 13 ergonomically designed, multifunctional work stations. Each work station is identical in its design but is used for different functions. The workstation functions are defined and allocated in the material flow control system. These functions can be changed at any time providing maximum flexibility to the operation. Currently 5 work stations are used as picking stations for production supply, 6 are available for goods issue, one workplace is reserved for returns and one as a clearing station. The items picked for production are delivered to the production areas on trolleys and transported via the in-floor conveyor to the required location within the facility.
A TGW conveyor loop links these 13 workplaces together and connects them to the automatic small-parts warehouse. This loop approach is an important design feature as it allows the trays containing the items to be sequenced to the work stations. The loop un-couples the TGW automated storage and retrieval machine activity from the sequencing requirement which allow the machines to operate in the most efficient way. The multi purpose loop is also used to deliver stacks of empty trays too and from the automated warehouse and the operation.
Electrostatic discharge (ESD) may cause serious damage to electronic equipment. ESD protection is therefore a major priority for Hella and plays an important role in the design, specification and operation of the logistics facility in Recklinghausen. A strictly maintained definition of the allowable charge range has to be accommodated through out the material handling system. The storage and transport trays used throughout the operation are constructed from conductive graphite and have to be transported on conductive materials all the time.
In order to meet the ESD requirement for the site TGW deployed the appropriate technologies and materials. Belt conveyors, for example, were provided with conveyor belts made of conductive material and steel slide plates were provided. The load handling devices were fitted with electro-conductive conveyor belts. The conveyor transfer devices were equipped with additional carbon brushes which provide earthing when the trays are transported over plastic belts. Additionally there are grounding bars to ensure a stable charge range along the entire conveyor system.
Special requirements combined with a tight timeline for the implementation of Hella's logistics centre in Recklinghausen posed a challenge. In less than five months TGW and its partners turned an empty hall into a fully operative logistics centre that includes a high degree of technology and automation.This was only made possible by the close cooperation between all participants from the Hella project and operational teams, the planner and architect and all the sub-system suppliers and partners. This integrated “teamwork” approach ensured that the solution was delivered and handed over to the Lila Logistik operational team on time.
The entire material handling equipment system has been provided by TGW without any pneumatic elements. All accumulation, transfer and lifting requirements are met by an electro-mechanical solution, which made the installation of a pneumatic system redundant.
The material flow control of the storage and conveyor system has a direct interface to the SAP-WM module and manages all material movement and flow of goods throughout the logistics centre. It directs the activity of the tray conveyor system and the in-floor conveyor system. The storage location management within the automated small-parts warehouse is also controlled and managed by the material flow control system.