October 23, 2003
Material and equipment storage can be a major concern for fabricators. Therefore, it is important to establish the purpose of a storage system and understand clearly what it needs to accomplish.
In its most basic form, a fabricator's storage area must be a secure, dry place of sufficient size to house required items. Location and ambient conditions are the critical factors.
In today's fast-paced material handling world, fabricators must consider the workable criteria before the project can be implemented. They must consider the basic cubic-feet requirements, as well as the environment required for the materials to be inventoried. And of course, location is highly important. Failure to consider it would compromise operating efficiency.
A modern inventory manager, unlike inventory managers of the past, has complete control of all the factors associated with material storage. With advances in technology, the inventory manager can build higher than was possible in the past. Fabricators also have the ability to make their buildings cold, warm, light, dark, dry, or moist with amazing precision.
While these advances can improve operating efficiency and add value to the product, fabricators still may feel daunted sitting at the concept stage of a storage system. To bring together all the variables and options available requires input from many areas of expertise. Here is a quick rundown of what needs to be considered.
New racking systems go far beyond simply stacking products. One of the objectives of these new racking system designs is to eliminate or reduce the aisles as much as possible.
Flow-through systems are designed under the concept of turning over inventory by making sure the older materials are used first. These systems (carton flow and pallet flow) allow maximum floor density and permit the materials to be where fabricators want them when they want them, always ready for transfer to the shipping dock or production, however it may be required.
First In, First Out (FIFO) is a form of flow-through system using a dynamic storage technique that allows the product to flow through the rack via gravity rollers, accumulating in an organized manner ready for the next step. These rollers are angled strategically at a pitch that permits the product to move forward. The speed is controlled by brakes acting on the rollers that prevent the loads from accelerating beyond the design speed.
Standard rack systems are complemented by a variety of material handling trucks that can be fully automated and attached to the racking. These are programmable logic-controlled and can be programmed to operate around the clock. Of course, the price tag and maintenance cost may scare a manager, but if the system has been properly applied, manufactured, and installed with the required precision and the proper scheduled maintenance, it can be a highly productive asset, depending on the fabricating system.
On the other hand, fork trucks exist that operate in narrow aisles only 54 inches wide, producing an increase of usable floor and air space that has a major impact in maximizing overall warehousing efficiency. These trucks have a side-loading feature that eliminates the need for the vehicles to turn to get the product out of its storage area.
The conventional 12-foot aisle is fast becoming a convention of the past.
Automated storage and retrieval systems (ASRSs) often are used to store smaller and frequently inventoried and retrieved parts. This type of system is self-contained and uses a series of traveling shelves or bins, usually traveling in a vertical configuration.
When parts are required, the individual identifies the part to the programmable logic controller, which in turn looks for the piece at a specific location and presents the requested item at the location of input. In addition to high speed and enhanced storage density, security is increased because the machine forces the operator to sign on to the system, logging the operator's identity. The system also tracks and identifies inventory items on its shelves.
A similar storage system that rotates products in a horizontal configuration is commonly known as a carousel system. It uses more floor space but can be less expensive.
Standard storage systems can be enhanced with the addition of a conveyor, which can be gravity operated or motorized. Personal computers can be used to direct products to the specific destination(s) as required. Like a modern highway with intersections, materials are diverted to predetermined areas.
The conveyor even can be configured to become part of a truck trailer. The addition of special racks for multilevel storage allows full use of the cargo area inside the trailer. Loading and unloading become much less labor intensive.
The logistics for this type of setup require precision in terms of weight and size. Variables must be reduced to make the system most effective. To maximize space and reduce the overall handling requirements, fabricators need to load parts or materials into properly sized bins and containers.
Planning the inventory system and proper product flow is necessary to ensure the best storage solution. Investment in the proper development of facilities and equipment using all modern advances will pay back handsomely in terms of labor, time, and money.