What are 6 general warehouse layout and design principles?

Thanks for the invite I leave the answer to experts specialists 

Hello Team,

Warehouse and distribution center (DC) design is a fascinating and absorbing topic, but alas, is often misunderstood. Regretfully, few people really understand the discipline of warehouse design and as a result, there are literally thousands of facilities that are underperforming.

To assist designers, I will outline the seven key principles that apply to warehouse and DC design. These have been compiled from a review of literature, discussions with industry specialists and materials handling companies, plus my own design experience over many years.

What are the important Warehouse Design principles one must understand?

One warning before I begin. The principles won’t make you into a seasoned designer, but they will help you understand the salient aspects of the design task, and how to think about and plan your facility for optimal performance.

1. Determine the objective of the facility

In a recent web discussion with a number of warehouse professionals, I asked their opinion on what were the critical principle of effective warehouse design.

This principle ranked at top of the list. The first step must involve defining the objectives and goals of the facility. What is it there for, what market does it service, is it part of a network, what types of goods will be stored, what is the anticipated life of the facility, will it be a greenfields site, or an existing facility?

To press the point, it is useful to write the objectives down so that all associated parties remain cognisant of the expected outcome – especially if timing, budget or resource issues during the project life tempt stakeholders to compromise operational or design goals.

2. Define volumes and functional requirements

The famous British Physician Dr Thomas Fuller once said: “Get the facts, or the facts will get you. And when you get them, get them right, or they will get you wrong”. This is an important lesson that was also affirmed by my learned web colleagues, and certainly one that has guided my own work throughout my career. Quite simply, the facts needed are:

a.    Quantities of products to be stored.

b.    The throughput velocities, including incoming goods, customer orders, interfacility transfers, dispatches and returns.

c.    The nature of orders and specific picking requirements, e.g. is picking performed in containers, pallets, cartons, inners, or single units?  Now if you are thinking that this is easy, think again. This is one of the hardest and most time-consuming components of a design project.Why? Rarely do enterprises have such data readily available. Designers must therefore ‘mine’ it from the enterprise as best they can. In cases where data is piecemeal or non existent, the designer must draw from his/her own experience to fix assumptions around volumetric estimates. This can be particularly challenging when heavy scrutiny is placed upon the designer to prove the concept, and is best performed with collaboration and agreement from the stakeholders involved.

d.    What functions need to be provided for?

It’s imperative that the designer understands all of the functions that are to be included on the site footprint, e.g. warehouse, offices, gantry cranes, loading docks, forklift charging areas, dangerous or hazardous goods, cool or cold rooms, clean rooms, manufacturing or packaging operations, staff facilities, etc. Equally important is that relative dependencies between functions are determined so that the designer can correctly frame functional proximities for best flow and operation by staff.

3. Match storage modes, it systems and mechanised technologies with volumes

Once the data has been analysed, the designer is ready for equipment selection. Be it static racking equipment, mezzanines and the like, or mechanical equipment such as conveyors, carousels, stacker cranes etc., all equipment and systems must be applied according to their purpose, limitations and fit with the volumes handled.

For instance, it is a waste if an automatic storage and retrieval system is installed, when a conventional racking system will suffice. Conversely, if the facts point to justification of a high-velocity automated system, it is foolish to ignore them for the sake of a more conventional system. A critical aspect of equipment selection is that the designer has expert knowledge of available equipment and technologies, and how to apply them.

This is a complex area that deserves careful consideration and the novice designer is well advised to seek advice from materials handling equipment and software suppliers, builders, and industry specialists to ensure that their design is well founded, robust and practical.

4. Flow

This aspect incited some interesting comments from my web conference colleagues. From their wise counsel and my own experience, I suggest that the skilful designers apply two immutable laws of flow.

a.    One-way flow. The best warehouse operations are those that apply this principle. Whether straight, clockwise, counter clockwise, up or down, make sure it flows in a one-way direction. But here’s a tip. Be cautious when dealing with international customers, where cultural and religious beliefs point to specific requirements. An interesting challenge that I experienced on a recent project was the Hindu philosophy of Vaastu Shastra. The customer politely indicated that the warehouse flow should be clockwise, heavy goods should be stored in the south west, with lighter product in the north east. The front door and offices should face east with entry to the site from the north. Needless to say, this provided an intriguing set of constraints that I happily applied to the design of both site and building. The key point here is that despite restraints, the designer should always err to the one-way flow principle.

b.    Flow vs. Capacity. The second rule of flow is that free movement has priority over storage capacity. If you are pressed with a choice, the pundits agree that it’s better to hold flow sacrosanct, compared with building more stock or storage equipment. Why? Long after the warehouse construction has been completed, a team has to operate efficiently and safely in the warehouse year after year. If the design compromises on the size and quantity of aisles, for sake of more stock holding, beware: this can cause suboptimal performance over the life of the facility.

5. Close to zero materials handling movements

A simple rule that says it all: keep the product handling by people to a minimum. Ideally from 3-5 touches of the product, while goods are the in the warehouse. Sadly, I have witnessed operations that handle goods up to 8 to 10 times. Normally there is severe design or building constraints applicable to such situations. But the outcome is evident in the maxim: ‘more touches, more cost’. Take note!

6. Evaluate your options

The developed concept design options must be evaluated to ensure that the objectives are achieved. The two common approaches to assessment are:

a.    Quantitative analysis: return investment, payback, cost per order to supply, cost per order cubic metre to name just a few.

b.    Qualitative analysis: reviewing the advantages and disadvantages of options considered. Ideally the evaluation is best performed both individually and in a team workshop environment. It’s amazing what can be revealed when a team collectively focuses its attention at a project. Despite the meticulous job the designer may have performed, a workshop can often reveal a late insight, idea, or missed detail that can significantly impact upon the end design.

7. Consult widely as the design process is multifaceted, and normally involves executives, managers, and operators – not to mention equipment suppliers, builders, architects, and councils.

As part of the development process all should be regularly consulted as to planning and legal requirements, operational needs, preferences, ideas and opinions.

In my experience, no one party has all the background and knowledge to implement a DC project. The best implementations typically features a cohesive and dedicated team charged with managing the project from early design phases through to completion.

Well, that concludes this short article on the Seven Principles of Warehouse and DC Design. I trust that you found them useful, and that your fascination of the design process has been sparked or invigorated. However, there’s one more design tip that I would like to share.

In applying the principles, please be mindful that the design of warehouses generally flows from the inside out, not from the outside in. In other words, materials handling system before building. This is most important to remember when dealing with architects and construction companies who are well qualified at ensuring the best construction and décor of a new building, but not necessarily at designing the best materials handling operations

Regards,

Saiyid

When considering the layout and operation of any warehouse system, there are fundamental principles that embody a general philosophy of good practice. The principles are:1) Using the most suitable unit load2) Making the best use of space3) Minimizing movement4) Controlling movement and location5) Providing safe, secure and environmentally sound conditions6) Maintaining at minimum overall operating cost

I would go for A as answer

Option a is the answer 

1) use one-story facility   2) use straight line or direct-flow of goods   2) use efficient material handling equipment   4) use effective storage plan   5) minimize aisle space (but do not constrain flow)   6) make maximum use of facility height

agree with expert answers above

choice 

# A) is the main 6 principle for Warehouse Layout & design.

There are several basic principles that apply to warehouse layout design and running an effective distribution center operation. Without the proper layout and design of your distribution center, no matter the square footage, you will be facing capacity issues, decrease in productivity, and storage inadequacies. This is a short list of these areas that should be addressed in your warehouse operations planning and facility layout. 

1. 1. Use the cube. Make sure you are utilizing the potential storage space/cube of the distribution center. Ensure that vertical space as well as individual location cubic capacity is fully utilized. Maximize cube as well as ground level square feet.
   2. Focus on slotting, replenishment, and location control system. These three activities form the backbone of the operation and should be given the appropriate attention. If they are cared for, much of the rest of the operation will run effectively.
   3. Maintain flexibility in the operation and layout. Planning for unknown future changes to the business or fulfillment model is a necessity to avoid unnecessary costs to make unplanned changes to the facility and operation. Don’t develop a layout or process that is inflexible or not scalable.
   4. Minimize congestion and interference with smooth flow. Avoid unnecessary congestion or overcrowding in the distribution center. The time lost due to overcrowding or congestion is significant.
   5. Use a variety of location storage media for slotting and reserve as dictated by item cubic velocity. The “one size fits all” approach rarely works to maximize efficiency in space and labor performance.
   6. Minimize travel walking time. Since more than half of the total labor time you pay for in the distribution center is spent walking, any efforts to reduce travel distance and time will pay off in reduced labor costs. Effective layout and slotting processes can help reduce walking time.
   7. Use conveyors for horizontal transport of product. Whenever possible, the use of a simple transfer conveyor system can improve operating efficiencies by reducing handlings and walk time. Make sure the cost of the equipment is justified. Conveyor selection is based on the size and weight of the product and the throughput volume. Accumulation has to be planned for in any conveyor design.
   8. Provide adequate accumulation and storage space on docks. Inefficiencies caused by lack of space on docks gets the operation off to a bad start and not only causes inefficiencies in the operations on the dock but ripples down to and can negatively affect other distribution center functions.
   9. Have enough dock doors. Since the expense of providing enough dock doors for inbound and outbound use is relatively small, and the impact of not having enough doors large, invest to make sure you are not slowing down the operation.
   10. Cross dock where possible. The ability to omit steps in the fulfillment process and take receipts directly to the packing/shipping function will save time. Consider using cross docking for backorder processing as the item is received.
   11. Use bar codes as much as possible. Consider applications to reduce labor and improve efficiency in as many areas of the fulfillment process as possible.
   12. Keep 10% of locations open and available. This may not be possible 100% of the time, but having space available to store inventory in picking and reserve locations is a key factor.
   13. Measure and report productivity to employees. The fact that most employees want to know what’s expected of them and how they are measuring up to those expectations should guide the reporting process in the warehouse to improve performance.
   14. Move as much product at one time as possible. Maximizing the product per trip will reduce the total trips and time required. Applications can be found in the picking, putaway, replenishment, etc. distribution center functions.
   15. Slotting procedures are critical. Try to provide primary pick space for one week’s average unit sales for each SKU. Focus on the top 10% of fast selling SKUs to insure that they are properly slotted. Make sure the slotting process is maintained as a dynamic, ongoing process.
   16. Have a well-designed pack station. Since the majority of distribution center labor is spent in the packing function, it makes sense to insure that all of the required materials are available for the packer and that adequate workspace is provided.
   17. Stagger shift start times. Make sure that your schedule for distribution center staff coincides with work being available. Consider off shift activities to minimize interference with other distribution center functions.
   18. Aisle mapping. A simple process that validates that the correct item is in the assigned location will save headaches in other distribution center activities.
   19. 80 – 20 rule. Indicates that 20% of your SKUs usually account for 80% of your unit sales, and as such should receive the attention of the distribution center staff to insure that they are processed as efficiently as possible. Create a “Hot Pick” zone for the fastest sellers.
   20. Single line orders. Batch-pick singles as much as possible.
   21. Automation. Provide for the level of automation that can be cost-justified based on your particular operation and cost structure. Look for 18 month payback as a guideline.
   22. Flow charts. Develop a process flow chart that tracks a receipt through the putaway process and an order from replenishment to shipping, showing the path and number of times the product is touched.
   23. Staff involvement. Involve your distribution center staff in decision making relating to facility layout or operations planning. Those closest to the process usually understand it best
   24. Make sure that you provide adequate lighting levels based on the type function to be performed. Processes requiring detailed inspection of documents should have a higher light level than a bulk storage zone in the distribution center
   25. Plan for an appropriate level of inspection. Don’t over inspect where not required. Pick the best function and inspection level to set quality requirements.
   26. Aisle widths in the distribution center:

• Conventional -  10–12 feet
• Narrow aisle -  8–9 feet
• Very Narrow Aisle -  44–66 inches

Option A)------------------------------------

Best answer is Option A) ========================