Leveraging WMS at Unilever

SSI Schaefer shares its experience bringing the warehouse processes of one of the
world’s most renowned companies up-to-date, while maintaining business as usual.

Whether food, body care products or detergents – by deciding to buy the brands of
Unilever Schweiz GmbH, every day 150 million people around the world convert
these products into part of their lives. The company was founded in 1929, employs
approximately 1,250 people and disposes of a wide range of 400 qualitative
branded products. Since July 2005 the four international business areas of
Unilever Schweiz – Foods, Home Care, Personal Care and Foods Solutions –
have been concentrated at the Thayngen, Switzerland site. The warehouse has now
been modernised – with SSI Schaefer as the general logistics contractor.

This retro-fit project has some fairly complex angles. These include several not necessarily compatible storage areas, warehouse extensions based on different
“control generations” and project management while the facility is in operation.
Quite a challenge to the Unilever and SSI Schaefer implementation teams, with the
warehouse operating a two-or-three shift system and 300 employees in the production and supply chain.

Starting out
The warehouse is subdivided into several sections corresponding to the product range (raw ingredients, packaging and equipment, finished products). The dried products are stored in a seven aisle, high bay warehouse. Additional storage areas for refrigerated and frozen products are immediately adjacent to production.

The Unilever warehouse in Thayngen has been in operation since 1997. Over the years the company has extended the warehouse several times. Stacker cranes are equipped with PLCs from different generations, Simatic S5 and Simatic S7. In 1997 an electrical overhead conveyor was installed in the pre-zone. A vertical conveyor transports goods to and from production over several different floor levels. A transfer carriage links production with the pre-zone. Both the lift and the transfer carriage date from 1995. Between the lift and the transfer carriage is a horizontal conveyor system, built in 1997 and featuring a Simatic S5 controller.

The objectives and requirements of Unilever Schweiz GmbH were as follows:
- Upgrade the outdated control technology to Simatic S7 to ensure that spare parts are available and that the system is reliable and stable, as well as to reduce operating costs and achieve performance improvements
- Implement WAMAS warehouse management and material flow systems for optimised control of goods flow across all sections of the warehouse, including online picking
- Integrate existing system components, such as the electrical overhead conveyor and vertical conveyor into the logistics system
- Interface to SAP

SSI Schaefer provided goods and services such as analysis, proposal and planning; project management with detailed restructuring scenarios; replacement of Simatic S5 with Simatic S7 control technology; implementation of WAMAS warehouse management, material flow, picking, stacker guidance and control systems as well as interfacing to SAP; commissioning the entire system and training Unilever
staff.

Changeover
In order to have a minimal impact on production and warehousing operations the SSI Schaefer team drew up a changeover plan, including transfer scenarios, in consultation with the customer. They also installed a test system in parallel to the existing system. Comprehensive testing and the gradual upgrading of the stacker cranes, trolleys, conveyors and lifts to Simatic S7 took place during weekend shutdowns or between 10 p.m. and 5 a.m. during the week. The old system could be up and running again within half an hour at any time.

The next phase saw the implementation of the WAMAS logistics software systems and the link to SAP. To test communication between SAP and WAMAS, the team installed an SAP test system and put specific processes “through their paces”.

Once the function tests were complete, all the article master data was transferred from the old system to WAMAS, the old Simatic S5 controllers removed and production with the new system started.

Flowing with software
The WAMAS software reorganised the automatic processes and goods flows, from goods-in and replenishment of production to processing complete pallets for goods-out. It records data consistently and logs all actions without impeding operatives in their work. The result is consistent transparency in the warehouse processes.

Staff enter orders into the SAP system and they are then forwarded to WAMAS. Once goods have been entered and marked at goods-in, pallets are either taken to the selected storage areas on stackers or automatically using the overhead conveyor. A three-shift system is in operation which sees raw materials and packaging material sent to the production area and the finished goods returned automatically to storage again via a simplified goods-in process. Goods-to-man picking is organised in two shifts. Once the desired quantity of goods has been taken, the remaining goods are automatically transported back to the high bay warehouse on the overhead conveyor.

Without paper
By introducing paperless order picking, Unilever has succeeded in significantly reducing the incidence of errors. The W-LAN routes orders directly to operatives’
terminals and operatives are directed to the shelves by the most efficient route. Operatives work in two shifts receiving goods-in, picking orders and preparing them for dispatch.