Although most of us tend to think of manufacturing when we hear the word lean, and of Mahayana Buddhism when we hear the word Zen, the primary principles of both translate directly to successful adoptions of warehouse management systems (WMS). Lean principles focus on process flow, optimization, waste elimination, problem solving and continuous improvements. The first principle of lean is flow, which lends itself to the Zen theory of being one with your environment.

Without question, these same principles guide the most successful WMS implementations. Learning how to translate the concepts of lean manufacturing and the Zen theories of flow to the adoption of a warehouse management system will certainly produce fast ROI and undisputable long-term operational improvements.

Creating Flow the Zen Way

You don't have to be a Zen practitioner to create "good flow." In the simplest of terms, you just need to think lean. Lean concepts start with process flow, and this concept easily translates to the warehouse. The phrase "being at one with things" is perfect when considering the term flow. Psychologist Mihaly Csikszentmihalyi proposed the theory of flow and stated that an individual is in the "flow state" when he becomes "absorbed in his activity" and when the "focus of awareness is narrowed down to the activity itself." He called this "action awareness merging."

Most likely, Csikszentmihalyi was not thinking about warehouse mapping and material management when he was discussing this Zen-like state, but his theory is exactly what warehouse optimization and lean principles are based upon. A well-run, efficient and error-proof warehouse facility is about placing people and products within the right flow.

A Zen-like process flow is lean. It is one where the employee is fully immersed in what he or she is doing. Instead of trying to think about the best method of efficiently moving inventory, the employee is simply doing the task. A WMS package helps facilitate this effortless flow. Not only will this speed the process of moving goods, it will create less opportunity for errors. Achieving this Zen state of employee movement can only be obtained through optimizing the physical aspects of the facility, the placement of materials and the movement of employees.

Mapping Out a Lean Warehouse

This definition of process flow starts well before any product begins to move onto the receiving dock. It starts with the "mapping"-or laying out-of the warehouse or production facility's stocking locations, work stations, and associated equipment. Some may say only large warehouses or production floors need this type of planning, but even small warehouse and manufacturing operations can benefit from a well-designed and thought out physical structure.

Good process flow requires planning, which begins with establishing basic warehouse zones, or large areas by which you can segregate products or activities. Reviewing your physical capacity, required transactional movements, and applicable raw materials or finished goods inventory is needed to properly define your zones. Typically, similar products or activities are placed within the same zone. This could be based on product dimensions, product characteristics (such as hazardous materials), or stocking requirements (such as temperature or physical containment considerations). Within each zone, space can be narrowed down to locations and bins. Stocking locations are designated to help further track goods for movement and usage.

A warehouse worker who is "at one with" his products and physical space is a productive worker who moves with the operational flow and not against it. This is a worker within a lean operational environment. To achieve this lean flow, not only must the facility's physical space be defined well, optimized usage of that space must also be obtained.

Optimization through Inventory Placement and Flow

Almost every warehouse must deal with obstacles when attempting to optimize inventory placement. These obstacles typically result from one of the following conditions: lack of prior analysis of inventory velocity history, lack of space in the warehouse, and limitations on storage space or special product needs. A common problem for employees to overcome in achieving their lean process flow is the transit time of inventory movement. Frequently, inventory is not stored in the warehouse in such a manner as to minimize the transit time for the picking of product.

Three steps can be taken in your warehouse operations to solve this problem. First, review product sales history to identify your high-volume items, which generally represent a limited amount of items that account for 80% of your total demand. Next, define a standard methodology for picking. This would represent a lean process flow for pulling goods within a facility. Commonly used methods include picking by sales order, picking by zone, etc. Finally, reorganize the warehouse so that the items identified as high-moving items are located in the areas most adjacent to the shipping area, with the highest volume items being the closest. The same holds true for raw material usage and placing those items most frequently consumed in an area or zone that is closest to the manufacturing plant floor.

Although relatively simple in nature, these three action steps will help minimize the total transit time to pick and ship an order. This reduction in transit time increases overall flow and productivity while simultaneously decreasing labor costs.

Eliminating Waste from Pick and Put-Away Processing

Enlarge this picture Figure 1. Processing multiple purchase orders simultaneously cuts down on waste.

By design, the pick and put-away process is labor intensive and, therefore, comes with inherent waste. These inefficiencies offer a wide range of options for the Zen master to streamline process flow and eliminate waste.

The receiving of incoming goods and the standard put-away process can present a bottleneck for any manufacturing plant or distributor. If performed without the principles of lean, the process can take hours or days to complete, and can delay both production and outgoing shipments. Applying the flow concept to this process is as simple as reviewing the recording of the goods received and the put-away location utilized, as well as the method of distributing those goods out to pending work orders or sales orders.

To eliminate waste, process multiple purchase orders simultaneously using bar coding and radio frequency (RF) devices (see Figure 1). Immediately have the WMS software check for open documents waiting for these goods, and then move these goods directly to the location of the pending activity. Today's WMS solutions can process a number of purchase orders or a pallet of inventory with one simple scan of a barcode. They can replenish interactively and notify the worker to immediately move the goods to a dock location for shipment (if a distributed item) or into an optimized holding location for production (if a manufactured item). Many times, it isn't necessary to receive the goods into the computer system and put them away, only to turn around and pull them again in a few hours.

Inefficient pick processing primarily occurs in warehouses where shipping is dominated by a sales order-based picking and small package shipping system. Typically, the picking process is managed by reviewing and fulfilling one sales order at a time regardless of the required products' physical locations within the warehouse.

Enlarge this picture Figure 2. Cart picking enables the warehouse personnel to pick a number of small package orders simultaneously.

For smaller types of inventory, this can be solved by deploying a process called "cart picking." The concept is simple, and it can drastically increase warehouse productivity. Instead of picking orders one by one, the warehouse personnel utilize a cart to pick a number of small package orders simultaneously (see Figure 2). Many WMS packages have this functionality built into the processing routines and are available for use for small package shipping.

In effect, the system sequences the picking process so that a single area or zone is utilized only once per "cart pick." Pickers place products for each order into bins within the cart. When driven by the system, a user cannot put the wrong product into the individual cart bins. Since a worker is moving from picking one order to multiple orders in essentially the same time period, the productivity of the worker increases exponentially.

Enlarge this picture Figure 3. For zone picking, WMS software instructs the worker to pull goods based on a given zone.

For larger inventory items, this waste can be eliminated by deploying a process called "zone picking." This pick method instructs users to pick goods based on the zone location of items and the worker's zone assignment (see Figure 3). Instead of picking orders one by one, the WMS software instructs the worker to pull goods based on a given zone. This eliminates unnecessary movement by giving the employee movement instructions based on the optimized path. As with cart picking, many WMS packages have this functionality built into their existing processing routines.

Problem Solving through Paper Reduction

Inventory accuracy is a key element for good operational flow. You cannot be "one with your activity" if you cannot locate the physical item needed. For the most part, high inventory error rates come from warehouse operations that are paper based.

Most organizations have a difficult time eliminating paper as part of their daily processing routine, and although RF and bar coding is now mainstream, this phenomenon of paper dependency is still particularly prevalent in the warehouse. Excessive paper usage within a warehouse is not only labor intensive, it opens the organization up to a multitude of user errors.

An optimized warehouse utilizes a WMS package to direct transactions, and thus employee work actions, throughout the day. From providing the next sales order to pick to inventory replenishments to cycle counting, a systematic approach to employee work flow is best managed through system-directed activities. When these activities are driven through a hand-held RF device and the scanning of barcode labels, the labor efficiencies substantially go up while user errors go down.

A WMS package can not only direct the employee to the next task, it can batch these tasks based on warehouse layout and priority, thus providing an optimized flow for the worker. Give the worker an RF device to scan the location code and product, which is then compared to the WMS instructions, and the worker not only becomes more efficient, he can also become virtually flawless.

The Zen Master's Work is Never Done

Kaizen is a common word within the world of lean manufacturing. It is a Japanese term that means continuous improvement. Broken down, kai means continuous and zen means improvement. Both the lean sensei and the Zen master know optimization doesn't happen overnight.

Optimization of a warehouse takes a solid WMS package, good planning, and, unfortunately, some trial and error along the way. That said, the warehouse can be one of the most smoothly operated areas within an organization. It offers substantial cost savings, efficiency improvements and reductions in user errors if lean concepts and a Zen flow are adopted properly.

For more information regarding WMS software, contact Technology Group International at (800) 837-0028 or visit www.tgiltd.com.