Room to grow
DaimlerChrysler freed up 80,000 square feet for new production capacity at its Warren, Mich. stamping plant when it added an automated storage and retrieval system.
By Megan McCoy, Associate Editor -- Modern Materials Handling, 9/1/2003
For years, DaimlerChrysler's stamping plant in Warren, Mich. floor staged all of its work-in-process (WIP) of vehicle hoods, doors, fenders and smaller parts. On a typical day, there were 200,000 stampings in portable racks spread across the 2.3 million square foot facility.
Then word came down, recalls Norm Malek, supervisor of facilities engineering, that an additional eight subassembly lines were being moved into the plant. Unfortunately, the facility was landlocked and its footprint could not be expanded. To make matters worse, the new production lines meant considerably more WIP was going to be in the plant at any time.
An automated storage and retrieval system (AS/RS) that added staging capacity yet freed floor space was the only option, says Dan Bluemer, material flow specialist.
Today, a 12-aisle, 4,850-location unit load AS/RS (Murata Machinery USA Inc., 704-394-6900) manages the flow of all WIP at the plant. In addition to freeing up 80,000 square feet of floor space, the system has made it possible to shift to a just-in-time pull system that delivers WIP to its next workstation only when needed.
Meanwhile, productivity has increased as has inventory control. 'Now we know for the first time precisely what we have in WIP and where it is,' says Bluemer.
|
DaimlerChrysler Stamping Plant Warren, Mich. |
|
Just as important, the $16 million system paid for itself in just one year as the plant pumped out stampings worth $25 million with the new production lines.
Stamping and staging
The pull system that the AS/RS made possible allows the plant to maintain a three-day cycle of processing raw steel into stamped parts and shipping them to seven assembly plants as well as the one next door.
The plant produces as many as 450 different stamped parts for Ram, Jeep, Durango and Dodge vehicles. Some come out of the presses ready for immediate shipment in portable racks. The remaining stamped parts require additional processing in the plant.
Before the AS/RS, racks of subassemblies were delivered by lift truck to a floor staging area in the general vicinity of the respective subassembly line. There, they sat until needed. Racks were tracked by a paper-based system.
Now, racks are bar coded and scanned before they are moved from the stamping area to an input station of the AS/RS for staging there. All information about the rack's contents is stored in a centralized database, tracking what parts are where.
'We know at the push of a button how many parts we have, when they were stamped, and where the parts are located at any given time,' says Bluemer.
With such precise tracking, the plant also has better quality control, says Mark Simoneta, the maintenance manager of the AS/RS. 'Based on the bar coded tags and sequential numbering, suspect parts can be easily contained. By identifying where the problem initiated, we can prevent suspect parts from hindering the subassembly process,' says Simoneta.
When parts are needed, the subassembly line electronically calls for them, literally pulling a rack from the AS/RS. The rack of retrieved parts is delivered by lift truck to the line just-in-time. This ensures that subassembly lines are never starved for parts and lift truck drivers are not performing unproductive tasks.
Installed in time for the launch of a new Dodge Ram truck, the AS/RS has turned out to be a big success in other ways too. It has created a cleaner and safer environment, added storage, and improved the productivity of the plant as a whole, according to all plant personnel. Moreover, 'it has created more business and future for the plant,' says Malek.
Putting a stamp on it
Coils and blanks of steel received on pallets (1) are transported directly to a destacker (2) at one of the plant's 13 press lines (3) . Each fully automated press line transfers the steel through all stamping stations.
A conveyor on the output end of a press line delivers each stamped part to a pick-up area (4) where plant personnel manually load it onto rack. Each rack is then tagged with a bar code, which identifies the rack and the parts in it. Scanning the tags sends the part's information to a database within the automated storage and retrieval system's (AS/RS) computer.
For transport to the AS/RS, racks are stacked two high on each of three carts pulled by a tugger. The racks are unloaded one at a time by lift truck at one of the AS/RS input stations (5). A fixed scanner reads the bar code tag on the rack, which then passes through a weight and dimensioning station. The weight is checked against what is expected by the database as the load is sized to ensure parts are within the putaway envelope. Once the input station approves the rack, it is stored randomly within the AS/RS (6).
Approximately 70% of racks filled with stamped parts are staged in the 12-aisle, 4,850-location AS/RS. This work-in-process is later retrieved on a first-in/first-out basis for delivery to the plant's subassembly stations. The remainder of racks are delivered on carts directly to shipping docks (7) where the parts are transported by rail or truck to one of eight assembly plants in the United States and Canada.
Work-in-process is called for automatically by individual subassembly workstations (8). The AS/RS retrieves the rack and delivers it to one of the output stations (5) . A lift truck picks up the rack and places it on a cart. A tugger delivers racks stacked two high on three carts to the designated assembly station. Lift trucks unstack the racks and place them line-side for subassembly.
Once the parts exit the subassembly station, they are manually placed into shipping racks and transported by lift trucks to designated shipping docks (9). There the parts are temporarily staged until they can be loaded onto a rail car or truck for delivery to one of the other seven assembly plants.
Outsourcing lift truck maintenance
08/31/2003Lift trucks and tweeting attachments
04/27/2009
View All On-Demand Webcasts
