Facility Layout and Work Flow

Facility Layout and Work Flow

Facility layout is not the first step, but the last action to take to position equipment, processes and people in a building. First create the right work flow, then the layout easily follows.

Your organization is different from others; products, equipment, processes, building shape, routing, inventory practice. Your work flow and subsequent layout will also be different.

Work flow starts with a combination of your own objectives, operating practices and geometry of the facility. But to these factors you will have to apply principles of productivity in order to create an effective flow and productive layout.

This article explains the components that will affect your flow, floor layout and facility design.

Objectives

A new layout may be needed to set up an added facility, or to adapt a facility already in operation. In both cases it is wise to plan carefully, because layouts tend to remain in place for years; better get this one right.

A layout will be planned for a given set of assumptions, and they should be carefully written and reviewed by all concerned. A production forecast will be a critical factor for instance, to anticipate both products and volumes expected. Your crystal ball should anticipate long term changes such as new products, new technology, changes in the economy. It is not necessary to detail how the layout will provide for those eventualities, nor even to build the space. But identify where a new addition should go if it is necessary in a few years time; don't block access now to a later action. Create a physical path now for later actions.

Cost constraints for the project must be considered as well as the time frame and calendar. Layout revisions are often planned over an extended time; first do this, later do that. Also define the extent to which production may be interrupted, and when.

Identify the internal resources who are capable of performing the work necessary, then judge whether they can perform their normal work and direct a layout simultaneously. The best project manager I ever knew was not able to run his normal assignment and a project at the same time, so take care in expecting a high level of performance in both tasks. Consultants such as my company are able to focus on the project, letting the client run the business. 

Operating practices

Many of your operating practices will affect a layout. Perhaps the most significant is inventory control. Do you practice just in time, or just in case? MRP or ERP, or another system? Where do you keep inventory throughout your process, both production and support? Is inventory current or a pack rat's delight? What do you want inventory to be after the move?

Computer hardware can be an issue in a relocation, both servers and points of use. Be sure to involve your own IT people and any vendors early in the project. Try to allow a parallel operation of IT systems to minimize risks. 

Telecommunications are a related concern to IT, although usually a bit simpler. Again, run in parallel if possible rather than a complete cutover from one system to another. 

Will you attempt to change major operating practices at the same time that you make a layout change? Then you are braver than I. One at a time is more likely to succeed, and if there is a problem you will find the answer more easily.

Geometry

Physical property characteristics will determine the final layout. Lot size, zoning, easements, covenants, drainage, access, parking; access from roads. Building dimensions; load bearing and partition walls; ceiling heights; floor loading; piping, drains, utilities supply; heat, ventilation, air conditioning requirements and availability; docks and materials access; stairs and elevators and ramps; personnel access; amenities such as rest rooms and food service; offices and other service areas; these are given factors in the current facility that will shape and limit any changes.

The process has an effect on layout as well. Equipment and fixtures and furniture take up a fixed amount of floor space. Materials handling and personnel movement, considering product and handling equipment, will dictate plant aisles.

Storage will use a significant amount of space, not only for product but also for the supply and support items kept in hand. There are many kinds of racks for storage, different square footage and different heights. Aisle requirements vary as well depending on the rack.

Support and administration will require space with a particular criteria.

Some functions will be difficult to relocate. They include plating and chemical treatment, water treatment, equipment in pits or on reinforced foundations, drains in the floor, stairways, elevators, structural mezzanines, etc. Processes with any kind of hazardous emission require special attention. Be sure to recognize these. If possible place them at the perimeter of the structure, but do not block off a future expansion.

Principles of productivity

To achieve a new layout, there must be an empty place on the floor to start. Usually a checkers game is possible, move one function to the empty space, the move something else, until you are through.

Flow as a general rule should not look like a bowl of spaghetti. A U shaped flow is often favored, or straight line flow. Move from start to finish of a process directly without doubling back if possible, whether the process is a automobile assembly or order processing or paying a tax bill.

Docks and doors are use to bring material in and out. Use one entry for receiving, another for shipping if possible; dedicate one to waste handling if there is significant waste. Docks for semis are higher than those for a low van, and both will be useful. Have ramps to allow wheeled vehicles to move in and out, to work in the parking lot.

If there are functions difficult to locate such as defined above, you may be more successful in layout if you first plan flow in and out of them, and later fit in departments that do not relate to them.

Consider early how incoming material will be staged and moved into the process, and how in process material will be handled. Plan for the most bulky and the most numerous first and then the flow of other material. 

Consider pedestrian traffic and separate it if possible from vehicle traffic.

Thanks for your attention; I'm happy to add to your perspective of industrial engineering and productivity.