There are so many types, variations, and factors complicated in the decision-making process, and now more than ever before the selection of racking style for storing your products is becoming less and less unavoidable as warehousing and operations evolve. Agv's (Automated Guided Vehicles) are an example of the latest elements that have been introduced into the mix. The most tasteless types of storehouse racking ready are:
1. Teardrop racking
2. Structural racking
3. Single-deep selective rack
4. Double-deep selective rack
5. Pushback
6. Drive in/Drive-thru
7. Conveyable racking or "Stack Rack"
8. Gravity flow rack
9. Cantilever
Basic Stamp Robot
Many other options for product storehouse exist, along with shelving, mobile shelving, and mezzanines, but for the sake of this "101" style course, we will stick to the basics. (For additional information on other product storehouse options, see my old record on rescue storehouse Space - Seven Proven Strategies.) To start the process of elimination for your facility, we first must ask the right questions.
The First Step: Discovery
1. What is my product?
The type or estimate of products or services that a business offers can vary greatly. In a dedicated manufacturing environment for example, perhaps no more than 3-5 Sku's (Stock keeping Units) exist. However, a 3Pl (a Third Party Logistics, or ageement warehousing, provider) can have thousands of Sku's depending on any estimate of factors. For example, how many customers are handled at that one facility? Or is this location dedicated to one customer? How many products of each customer's are at this location? Does the 3Pl specialize in only one type of product storehouse and handling?
Product type is a key factor. Is the product stored in barrels, containers, bags, pieces or cartons? Is it palletized? What are the pallet dimensions when loaded? How much does it weight? Does the product hang over the pallet?
With so many questions, we should start by saying that, if possible, floor-stacking your product, the act of stacking on palletized product on top of another, is the particular best formula to use with regards to both cost and storehouse density. Floor-stacking does not need the buy of storehouse racking that takes up vital storehouse space, development this the favorite formula of 3Pl's in any place (much to the chagrin of pallet racking manufacturers and distributors!) The potential to floor-stack a product is based on the stability of the loaded pallet combined with the product's capacity to handle the weight without buckling on itself. But even if it can handle the weight, floor-stacked product should never exceed four pallets high for stability purposes.
If your business is not a 3Pl, or if floor-stacking your product is not possible, then you need to value exactly what it is you are seeing to store. How many distinct Sku's do you have? How much of each Sku is there at any one time? What are the sizes of each Sku? Does 80% of your business draw from 20% of your total Sku's? All of these answers play a role in determining your racking preference.
Also, the smart designer will plan not just for the total maximum amount, but will also add 20%-30% to that shape in order to catalogue for time to come business growth. While pallet positions sitting empty for a integrate of years waiting for the business to grow are a waste of space, using tool that is designed to advance with you wherever potential is always the engaging option.
2. What is my throughput and velocity?
Basically, how much product (raw, finished, and mid-process) goes through your installation at any one time, where does your product go within your installation and how fast is your product engaging from receiving to shipping? Does some of it sit for a while before it ships out? Do you have a dozen or so forklifts transporting product back and forth at any one given moment in time or does your business have only one forklift driver? Are you a manufacturing plant using "Just In Time" processes? Does your product expire? Do you use Fifo (first in, first out) or Lifo (last in, first out,) or neither?
3. What kind of material handling tool do I have?
The particular best query to ask at this point is the following: Are my forklifts going to rule the racking I use, or is the racking I use going to rule the forklifts I get? Where are you in the process? If you already own (and are locked into) the lift trucks you have (or are acquiring,) then you naturally have to work within the confines and limitations of that equipment.
If, however, you have the luxury of being in the enviable position of having a selection of lift truck and storehouse formula to use, then the only limitation you have is your existing budget. If you are not in a position to buy new (or even used) forklifts, then ask yourself if you wait until you are.
Understand that the material handling tool you use is vital in this decision. Believe it or not, I once heard of a situation where the racking sales rep didn't ask about nor look at the type of forklifts that his customer was using, and when double-deep racking was proposed, the fresh-out-of-college storehouse manager didn't think about that either. Thank God that the project never made it past the "Letter of Intent" stage, because those four-wheel sit-down forklifts would have had a hard time picking product out of the second (two-deep) pallet position without a reach mechanism!
4. How much room do I have to work with?
The dimensions needed go beyond (length) x (width) x (height). The forklift limitations described above in query #3 have to be taken into account, which includes the right angle stack aisle clearance width vital for safe rack interaction. Also, take into catalogue the placement of your other tool (machine tools, battery charging station, packaging area,) as well as your shipping and receiving areas.
Do you need to create more room? See my old record on rescue storehouse Space - Seven Proven Strategies here.
5. How much flexibility do I need?
The savvy storehouse layout planner will understand that the only constant in business (besides taxes) is change. That includes product sizes, volume, throughput and velocity, or even installation moves or consolidations. You need to take into catalogue that today's product may be tomorrow's trash. Flexibility is an absolute must when considering storehouse alternatives.
Questions to ask are: How quickly can I modify this rack? What modification limitations do I have with this? If I need to change storehouse equipment, how will that succeed my handling tool (lift trucks, etc...)? How much time do I have to change tool over if my product changes? What is the lead time when I order new rack?
An additional hint: Whenever you are seeing to order anything new, regardless if it is rack, lift trucks, or office supplies, get the lead time. Always, always, always get the lead time. When you get that time frame, you then can work backwards from the longest lead time potential to get the last day you can make a decision on a project. For example, if today is July 1st, you need new storehouse rack delivered and installed by no later than September 1st, delivery lead times are 4-6 weeks out and the project will take one full week to install, then the last day for you to make a decision will be 7 weeks before September 1st, or July 14th.
If you want to factor in Murphy's Law, as the savvy storehouse layout planner will do, you will make your decision by July 7th.
The Next Step: Solutions
Now that we have our questions answered, we can now move on to which type of storehouse clarification may work best. Again, there are other options available, and all options should be explored, but we will stick to the most tasteless for simplicity's sake.
1. Teardrop racking
Teardrop and Structural Racking (#2 below) are not methods of storage, they are distinct designs of rack, but the two varying styles do need to be covered as there are differences in capacities and cost. The teardrop create is a hole punched into roll-formed racking in the shape of an upside-down tear. The beams have a locking gadget that slides into the large hole in the frame and locks down into place. Holes are typically spaced 2" apart gift placement flexibility, and the formula of installation will save money on the labor needed to assemble the racking.
Most teardrop style racking manufacturers also make interchangeable racking, meaning one manufacturer's racking can be used with another's. This means you're not "locked in" to any one given rack producer, which offers you flexibility later on down the line. This is also the most sought-after racking in the middle of the two, meaning should you wish to offer your rack on the used store later on down the line, you can be assured that, more than likely, there will be a query for it if it is in good shape.
2. Structural racking
The Structural create of racking is designed for heavy-duty applications. A stronger steel create is used and beams are bolted on to the uprights or frames instead of being slid into place. While structural steel does offer a stronger rack module with a higher capacity, it is more costly when compared to teardrop both in the tool buy and in the installation. Structural racking has its place, and in some cases may be mandatory. Ask a grand counselor for aid in determining your needs.
3. Single-deep selective rack
This is, by far, the most tasteless storehouse clarification I see, and for good reason. particular deep selective rack interacts with most if not all types of forklifts, can fit into roughly any environment, and offers the most flexibility. While it is not the most efficient use of floor space available, it rates top in selectivity. You can always pick every pallet at any time in any place in single-deep selective rack.
4. Double-deep selective rack
Offering more storehouse density (up to 40% more than particular deep selective rack in some applications,) the only true drawback to double-deep storehouse racking is the necessity for a special type of forklift, the reach truck. The reach truck is a specialty type of forklift that is designed primarily for rack interaction and product staging to shipping or pallet pick-up from receiving. High throughput and velocity operations will benefit the most from this storehouse formula as this environment normally requires dedicated forklifts such as the four-wheel sit-down lift trucks and the walkie-riders, which can handle most of the other pallet vehicle functions throughout the facility.
If you have a high ceiling, this racking also offers a larger module footprint than single-deep racking, thus development for a more garage system, and some reach trucks can now lift pallets to 37' high! overall ready square footage must be weighed against the total Sku count however since selectivity decreases.
5. Pushback
A Lifo application, pushback racking systems can typically go in any place from 2-5 pallets deep. Pallets are placed by forklift on a gravity-controlled cart within the rack. If there is product already on a cart and space is ready behind it, the forklift (pallet) pushes the cart back and the new pallet is placed on the cart in front of the customary pallet. Unloading of the pallets naturally works in reverse, with the full cart behind the picked pallet engaging forward after the picked pallet is unloaded from the rack.
Selectivity decreases, but pallet storehouse density increases. Low to mid-range Sku counts work best here.
6. Drive in/Drive-thru
A low Sku, high density clarification that can be utilized for both Lifo (Drive-In) and Fifo (Drive-thru) storehouse methods. Drive in/thru modules use rails that act as pallet supports, and run as deep as the theory provides, eliminating aisles and thus addition density and cube utilization. One qoute with this storehouse formula is called "Honeycombing," whereas particular slots can become un-utilized until pallets in front (or behind) of the slots are removed.
Where pushback racking offers more versatile storehouse than Drive in/thru racking because each lane flows independently, Drive In/Thru may be have the most storehouse density in the middle of the two solutions. There is a trade-off, and a grand counselor can offer answers.
7. Conveyable racking or "Stack Rack"
Applications without fixed racking create requirements, changing ready racking space, volatile storehouse needs, granular product stored in large bulk bags, or other special products may need Conveyable or "stack rack." This is a great application for low to mid-range velocity and throughput applications as you are no longer confined to a exact rack design. When not in use (and depending on the design,) these racks typically stack and nest within themselves for easy storage.
8. Gravity flow rack
Flow racking is a specialty type of racking most generally found in pick modules in a Fifo system, but is also found in bulk racking systems as well.
In a typical bulk rack module, pallets are loaded onto the module onto the back end, and the pallets "flow" via flow-rails to the front picking end, automatically rotating stock. This theory works best with a low to mid-range estimate of Sku's (depending on ready space) and is one of the densest storehouse methods available. normally the estimate of forklifts and manpower can be reduced using this technique as well.
In a typical pick module system, flow racking is the lowest row of racking and the top levels are for "replenishment." Full pallets are brought down from the replenishment levels and are loaded into the rear of the system. They then flow via gravity into the front or face of the system, which is the pick area. Pickers are instructed via pick marker (or a pick to light or other similar system) to pick off of the pallet either cartons or pieces to fulfill an order as it proceeds down the theory via conveyor.
9. Cantilever
Cantilever racking is other specialty type of racking. It is found in manufacturing or lumber yards primarily, but can be used in any place longer product is stored. This can include drywall, sheets of plywood or metal, steel bars used in processes, tubular products, or any other elongated material.
An additional hint: When planning your product placement in the warehouse, use the 80/20 rule mentioned before. normally 80% of your business comes from 20% of your product. catalogue for that by placing the 20% of the product closest to the shipping, processing, or picking areas. Placing the least used product in the pallet positions that are the furthest away, then working your way in, will help you in your planning.
This information should serve as a guide and a great beginning point for anything seeing to lay out a storehouse floor plan. In the upcoming weeks, I will go into each type of rack with greater detail in order to assist with the intricacies of each style.
storage Racking 101 - Basic Rack Styles and the 5 Questions You Must Ask