The mantra for going lean is “eliminate waste” of all types, with “waste” being whatever customers are not interested in paying for. In today’s competitive and rapidly changing market environment, going lean is both a necessity and a challenge, particularly in manufacturing. In no area of manufacturing is the elimination of waste more important than in the delivery of materials to production.

At Pack Mule, we work closely with the users of our products to help them address this challenge by adopting “lean material flow” techniques. By far, the primary waste reduction opportunity lies in reduction of the size of the operation’s forklift fleet and the scope of a planned conveyor system, in favor of other tools such as electric burden carriers, electric tow vehicles and towable carts and towable pallet jacks, carrying materials at designated intervals on repetitive paths to production.

Lean Material Flow in Action!

At one of Pack Mule customer’s auto manufacturing plant operating around the clock on a three shift basis where lean material flow has been embraced, for example, the main production facility employs about an equal number of forklifts and electric tow vehicles (about 50 of each) and literally hundreds, if not over a thousand, of towable carts and racks (for a variety of components – flow racks with fasteners, racks of engines, etc.). Forklifts are used only where vertical movement of materials is required. Tractor trailers deliver these towable carts with components and subassemblies from nearby supplier facilities, and the electric tow vehicles pull 8 to 10 of these carts from these tractor trailers and then deliver them to the station in the production line as and when they are needed. Consistent with lean’s 5S principle, there is of course no excess inventory at the production line, so the tow vehicles and towable trailers must constantly replenish materials to production to avoid interruptions due to shortages. Every “tool” is performing the job for which it is designed – so that electric tow tractors and towable carts are used (instead of forklifts) to move materials horizontally, resulting in substantial cost savings and increased productivity.

Safety is Paramount!

One of the biggest forms of waste in industry today comes from in-plant accidents, and the substantial majority of all accidents associated with the movement of materials is attributable to the use of forklift trucks. According to statistics provided by OSHA and the ITA, over 90% of all forklift trucks will be involved in accidents over their useful lives, and 42.5% of all forklift accidents that result in fatalities occur in manufacturing facilities. So use of electric tow tractors and towable trailers can substantially reduce the waste that comes from forklift accidents.

Don’t Just Take Our Word for It!

One of the world’s leading experts on lean logistics is Michel Baudin. In his seminal work, LEAN LOGISTICS – The Nuts and Bolts of Delivering Materials and Goods, published in 2004, Baudin states, “The key message about in-plant transportation is that the system needs to be customized to the needs of the plant, using a variety of methods.” (Page 71).

In regards to the relative strengths of forklifts, Baudin states: “Forklifts are such common devices that they immediately come to mind in any discussion of in-plant transportation. They are versatile and powerful, but they are not without disadvantages:

  • They cost tens of thousands of dollars.
  • They can only be operated by specially trained drivers.
  • They are a safety hazard and must be constrained to run in designated areas.
  • They are appropriate for moving pallet-sized loads but not smaller quantities. (Page 51).

Baudin observes: “Neither the forklift nor the individual push cart is adequate to deliver thousands of items in box quantifies at multiple locations every half hour, as is commonly needed in the automobile industry. The solution then is to hook up carts into a train and pull them around designated routes with a tugging engine whose driver also loads and unloads the boxes along the way.” (Page 53).

Baudin then introduces the “milk run” concept.

The forklift and pallet model is a poor fit to the repeatable flow of items between the same locations. Pushcarts or trains of two carts traveling on fixed routes at fixed intervals, like city buses and subways, picking up and dropping off quantities of materials that are usually less than full pallet loads, provide a cheaper, more reliable, and more predictive system.
This is the in-plant version of the “milk run” concept…. (Page 68).

He then describes an operation in which the milk run operator from the materials department deposits full bins and picks up empties on the racks lining the edges of the manufacturing islands. These may be flow racks feeding the cells directly, or the parts may be kitted for assembly by a water spider from the production department. (Page 68-69).

Baudin’s conclusion is that each operation must be analyzed to determine the requirements and the separate tasks that must be accomplished to meet those requirements. Potentially, the system is designed to position each possible tool (forklifts, AGVs, conveyors, electric burden carriers, electric stock chasers, pallet jacks, push carts, tow carts and electric tuggers) to carry out the function which it can perform more efficiently than the other tools. Any other approach will result in waste and is thus not an optimal solution from a lean perspective.

Pack Mule offers a wide range of both Electric Tow Tractors and Towable Trailers. And all these products can be configured to the end users specific needs and applications. This combination is unique to Pack Mule, so call us today for a free consultation with one of Pack Mule’s experienced Sales Engineers. Pack Mule is even willing to create a new product, configured to the customer’s exact needs, and allow the customer to try the product on a risk free basis for up to a week.

Contact us today for details….