In many North American distribution centers, it is not uncommon to have 30-50%, or higher, direct labor force with a mother tongue other than English. This can lead to difficulties training new associates who may be forced to deal with English language instructions or paperwork. Voice technology offers some benefit in this area by enabling operators to interface with the computer in their own language.
The primary advantage of voice recognition technology, however, is that it leaves a worker’s hands free to perform the intended jobs of driving a pallet jack and selecting orders. In fact in many applications, voice technology eliminates paper from the warehouse. Workers don’t carry around a lot of paper or make mistakes by reading the wrong thing.
The systems are simple. The radio devise is usually worn on a belt. In addition, the worker wears a headset with earphone and microphone. For hygienic reasons, headsets are usually dedicated to specific individual workers. These two components provide a radio link to the warehouse management system (WMS).
Once selections orders have been loaded into the system, a voice prompts the order selector to go to a specific warehouse location. On arrival, the selector verifies the location by reading back a random series of check digits posted at the selection slot. After location verification, the system issues instructions to pick a given number of cartons. When selection is complete, the worker says “ready” into the microphone or “pick zero” if the instruction was not understood completely. Those two statements can be customized by the user to make the system even easier for workers to use.
With voice systems, workers don’t have to read or fumble with paper. They don’t have to press keys on a transmitter console. Hands are free; eyes are free, so the worker focuses entirely on the picking activity. This ease of use is particularly important in hostile environments such as a freezer.
Two speech systems
Voice systems can be speaker dependent or speaker independent. The two possibilities have important differences. With a speaker dependent system, each worker develops a specific voice template before beginning to use the system. This template resides permanently in the computer so that the system will always recognize the worker’s voice and speech patterns. Speaker dependent systems are usually preferred in environments where worker accuracy is vital.
Speaker independent systems are much like other automated voice systems such as directory assistance on the telephone. With a speaker independent system, workers must be trained to understand the system rather than the system understanding the workers as in a speaker dependent system. A speaker independent system limits the number of words that a worker can use to communicate with the computer. The main disadvantage of a speaker independent system is that more time is required to use it.
Synthetic speech systems
Voice directed order selection uses synthetic speech, which can be produced in two ways. Some systems use text-to-speech technology, which results in a computer voice speaking to the worker. The other technology is digitized speech that uses a human voice to communicate with the worker and this works best in applications that utilize a limited vocabulary.
Preventing worker mistakes
While the technology is great, workers can still make mistakes. The system may tell a worker to pull five cases, and the selector may actually take only four cases. Workers also sometimes still pull product from the wrong slot. That happens most often when the selector has the verification digits memorized or reads them into the system before actually arriving at the selection slot. To keep that from happening, some warehouse operators make the verification digits hard to see from a distance. For instance, the slot identification may be on the front of the rack and the check digits may be posted somewhere back in the rack.
Two factors have a big impact on order selector productivity. The first is the slot location. If the product is easy to reach, productivity goes up. If the selector has to reach up to the picking slot, it takes more time. Reducing travel time between picking slots helps as well. The second factor involves the verification digits. The sequence should be no longer than three digits; two check digits are ideal for best productivity.
January 5th, 2010
More than ever companies are reducing costs to remain competitive, while keeping an eye on further improving their responsiveness to customer demand. Supply chain improvement is a way for companies to keep increasing efficiency, making it one of the last frontiers on which companies can compete to reduce cost and improve customer service levels.
Flexibility in design is critical to ongoing operational success. By accurately projecting volume growth and product variability, with an eye to ‘keeping all options open’ while providing the optimum workable solution for today’s needs means that flexibility must be built into the material handling system.
Supply chain execution demands a design that best facilitates speedy, timely, accurate delivery with an emphasis on the ‘perfect order.’ This results in distribution centers designed for velocity, with higher volume items located at the beginning of the order picking path.
For maximum efficiency such a warehouse is re-slotted on an ongoing basis. Some operations may even look at the movement, cube, and velocity of items and rearrange items on almost a weekly basis cutting travel time and keeping productivity high.
Order picking is one of the most important activities to optimize since it is the most labor intensive activity that goes on in a DC. It’s where you have the greatest opportunity for bottlenecks and pickpack slowdowns.
By re-slotting your inventory at regular intervals -locating stock items to reduce travel time and increase velocity - you can go a long way toward improving facility efficiency. If you compare an efficiently slotted warehouse with an inefficient one, you could see a 25% to 30% difference in labor productivity.
When it comes to efforts to derive further efficiencies from automated and mechanical equipment there are important considerations to be made, one of the most important considerations is building flexibility into the system.
Before forging ahead the current physical distribution infrastructure and operations must be assessed. This includes examining the existing operations as well as buildings and sites to identify constraints, capacities and opportunities. Very often an operations audit conducted prior to implementation of any new initiatives will result in significant cost savings and productivity increases.
When KOM conducts an audit 52 weeks of order flow history are analyzed to get a sense of inventory item movement over time. Information is captured on sales of units, pieces, cases and pallets in order to identify the volume and item peaks and valleys. This provides an irrefutable portrait of what kind of pressures a facility experiences during the year.
In addition to order history KOM looks at the company’s individual customer order files to see whether orders typically comprise one line item, 100 line items or 1000 line items. Most warehouses are a hybrid of two order types - large and small. You attack them differently. Large orders get picked conventionally while smaller items might get picked to totes.
Today the real gains have been made in the area of the capture, transfer and processing of information; not only in the quantity and availability, but the incredible speed at which it can be handled and responded to.
The physical materials handling equipment has had to evolve to keep pace with the speed of information capture and demand for faster order fulfillment response times.
With electronic information transfer, and particularly the accessibility offered by the internet, the consumer and business now expect total transparency regarding product availability and deliver schedules.
Business now faces orders arriving from many different sources, all electronically. Strategies have been implemented to process and re-direct these orders almost immediately to the most effective location for fulfillment.
Not only has the physical materials handling equipment evolved to keep pace with the speed of information capture and demand for faster order fulfillment cycles, but so has the communication with these devices and steps taken to integrate them into a complete system providing as much flexibility as possible.
Today, many companies are taking a second look at automated methods of receiving and selecting as a way of improving efficiencies.
If systems are designed properly and are thought through based on a thorough analysis of sound historical data then there will be flexibility built into them because flexibility is an important quality of an effective and successful design.
Most systems, however, do not have enough flexibility built into them. This is because many companies are dealing with the requirements of the day-to-day, and don’t have the time to look to the future when solving the problems of today. Not to mention that uncertainty in the direction or growth of most businesses may make it difficult to come up with firm projections. Markets, technology, competition are always changing leading some planners to argue that - “the future.. it ain’t what it used to be.”
Regardless of the reasons against built-in flexibility it’s one of the most effective ways to address changing requirements as they emerge, and emerge they will for the only real constant is change.
Flexibility can be built into your material handling system from the ground up in a number of ways by making a commitment to ensure that it is prevalent throughout the design.
For the Building: choose the right site,
- build in the column bays to provide for multiple layout options,
- build to a clear height.
For the Racking - design a structure that allows for flexibility so that you can move from single deep to double deep without changing the structure.
For the Shelving - allow for future levels of shelving units to be added to the original design.
For the Numbering System - this can be designed to accommodate item proliferation if considered up front in the design of this element of the system.
For the IT Systems - there can be an eye to growth that provides for flexibility in the design.
If the original design is done well, then a retrofit down the road is of course much easier.
A good source for companies looking to learn more about flexible material handling is The Material Handling Handbook, sponsored by the American Society of Mechanical Engineers and the International Material Management Society, published by John Wiley & Sons.
October 13th, 2009