Ship by mañana

Tortilla maker Mission Foods delivers orders within 24 hours and with a 700% jump in productivity.

By -- Modern Materials Handling, 8/1/2000

Mañana, the Spanish word for tomorrow, has a very positive connotation at the Dallas distribution center for Mission Foods, world's largest manufacturer of tortilla-based food products.

In fact, the company's overriding mission is to deliver, not just ship, orders within a 24 hour window.

"The name of the game in tortillas," says Vance Brack, director of logistics, "is product freshness. We have to turn almost all of our inventory on a daily basis."

And that can be a hard goal to achieve when you ship more than 17,000 cases a day, six days a week, of a wide variety of Mexican food brands.

But at its Dallas distribution center (DC), Mission Foods now delivers fresh tortillas and other goods to local markets with a seven-fold increase in throughput productivity over its previous warehouse system. On a labor hr basis, order picking has zoomed to 700 cases/hour. That rate compares to 100 cases/hour previously. A future goal: shipping 900 cases/manhour.

Elsewhere, productivity has improved too. Loading times for delivery trucks to pick up at the DC's shipping docks have been cut tremendously, says Brack. Times once as long as 2 hour are now reduced to just 30 to 40 minutes, including completing paperwork, explains Larissa Ventura, Dallas DC manager.

In addition, all products are handled fewer times from Mission Foods' tortilla baking ovens to the customer. Within the DC's order picking and fulfillment steps, handling occurs two or three times now, compared to eight or nine earlier, says Ventura.

As a result, the warehouse expects to re-deploy 40% of the associates involved in the pick task to other warehouse and manufacturing duties.

High-density, dynamic materials flow is the major force behind these improvements (LB International, www.loadbank.com ). A two-tier (mezzanine and floor level) belt conveyor picking module also helps speed products to customers.

High-density, controlled flow

Ernest Harris, vice president, logistics, and his team are gradually changing the old ways of distribution and the company culture at its 14 U.S. production plants and related DCs. The 150,000 sq. ft. Dallas DC is the second in a series of warehouses, after a Los Angeles DC, to undergo a new systems implementation.

"High-density, controlled materials flow without manual intervention," Harris says, "is our key concept. We are installing systems that are designed to move product through the warehouse-not to store it-in a way that we can measure and control that flow.

"The worst thing that you can do with our food products is to store them. We want to facilitate movement of product to our customer."

Put another way, Harris says that given "the time sensitive nature of the fresh food business, any throughput gains in the DC lead to better customer service. They also eliminate warehousing as a constraint to the plant's production capability."

With high throughput from the high-density, dynamic flow staging systems and the pick-to-belt module, Harris keeps both his internal customer, the plant, and his many external customers highly satisfied.

Previously, Mission Foods stacked most of its products at the Dallas DC on pallets on the floor, Brack explains. But, with the company's explosive growth, this warehouse, like some others in the company, became a "choke point in the company's supply chain."

More productive staging and picking systems were needed to address growth factors. The materials handling systems had to be able to successfully handle the complexity associated with hundreds of stock keeping units (SKUs) and a wide variety of cartons and tray sizes.

"It is an on-going challenge to integrate these complexities and fully utilize the trailer cube space available," says Brack.

The Dallas-Ft. Worth market dictates that the DC be primarily a case picking, rather than a pallet picking, environment. Some 70% to 80% of all orders are picked as boxes and trays of product; the rest is bulk picked.

The DC, on average, ships some 9,120 cases daily, six days a week, in its direct-to-store (DSD) business. DSD delivery trucks cover 38 local routes in the Dallas-Ft. Worth area. Over-the-road trucks (OTR) will carry another 8,080 cases daily to the rest of the company's business. DSD and OTR loadouts are scheduled at different times so they don't conflict and cause congestion, Ventura explains.

Simulating the system

To help decide how best to resolve this scenario of distribution issues, several computer simulation models were tested.

Simulation, says Harris, "is a powerful tool. It streamlines the design process. It allows you to evaluate multiple designs in very short periods of time. More importantly, the simulation model can become a management tool that enables me to plan, manage, and evaluate alternatives."

For example, Harris could examine DC staffing, both long-range and short range. He also studied volume throughput issues.

Modeling helped determine the specific configuration of the DC with two types of dynamic staging systems and the two-tier, pick-to-belt module, says Brack. And it set levels of inventory, in days of items on hand, for SKUs where perishability is less critical.

The predominant pallet staging system in Dallas moves loads in slightly angled racks by using an inflatable hose, powered with compressed air, to control the force of gravity. The hose runs beneath a wheeled track in the system. When inflated, the hose lifts the wheels up under a load, facilitating its travel down the sloped lane.

Elsewhere in the DC, the racking is totally level. An oscillating air cylinder tracks forward or back. When the track moves forward, the load moves forward. When the track moves backward, the load is secured by an air-driven brake pad or by a one-way flipper device.

In each of these systems, radio frequency control technology directs load movements, from loading the system to keeping loads moving and accumulating at the discharge end as required. Hand-held RF terminals on the forklifts enable operators to signal the staging system and to control load moves as they perform putaway and picking.

As configured for Dallas, these two staging systems provide a total of 2,062 pallet positions with 229 lanes for pallet movement. Within the pick-to-belt module, the staging systems facilitate high daily order throughput volumes. Each day nearly 11,000 totes and trays as well as about 180 mixed pallets will be picked in the module. With zone picking, "four orders instead of just one order can be picked simultaneously," says Brack.

Picking for mixed pallet building varies by the velocity with which individual SKUs move through the DC:

• Fast movers are picked to conveyors on the floor and mezzanine levels; the conveyor moves along the face of these SKUs.

• For slower movers, pickers move up and down the aisles adjacent to walk-back lanes in the staging system, and pick items for orders.

• Finally, for the very slow moving SKUs, items are pulled from floor stacked pallets by an operator in a tugger vehicle pulling a series of carts. Each cart holds at least two orders.

Conveyed to a floor-level sortation area, orders on pallets are then sorted by customer and by DSD (direct-to-store delivery) or by over-the-road (OTR) truck. Then orders are staged a final time, before shipping. Orders go into one of two high-density staging systems. DSD orders go into a DSD unit of 15 lanes, with loads 10 deep and three high. OTR orders go into an OTR unit of six lanes, with loads 14 deep and two high.

From receiving to this final staging area, Mission Foods' products now flow smoothly through the DC, maintaining fresh food requirements. The previous supply process, Brack says, operated like "islands of activities," lacking any real integration.

The new warehouse system has been a catalyst to cause the various supply chain partners to redesign the work flow and has linked and integrated the various partners in a new and more effective way," he adds. And there's more teamwork, as Ventura suggests, keeping goods moving.

Brack adds, "The logistics goal within our company is world class customer service with an emphasis on ever fresher product," he adds. "The materials handling advances in Dallas and in Tempe, Ariz.; Los Angeles; and Fife, Wash. all serve to make our goal a reality."