How to design a workstation

The workstation is a central focal point for optimizing human factors in production areas, whether a stationary work bench or a flexible position on a moving line. Common shortcomings to be overcome are:
  • Positioning the item to be worked on at a height and orientation not suitable for efficient work.
  • Inadequate fixturing of the item.
  • Suboptimal provisions for handling parts and materials.
  • A variety of layout issues.

Topics

Applying the principles Steps
  1. Define optimal height and orientation
  2. Identify a fixture or holder
  3. Determine material handling requirements
  4. Define tool and material needs and their location
  5. Review other issues for applicability
Workstation case examples From workstation to production line
Unfriendly1 Unfriendly2
Poor interface with the product
The traditional approach for setting up a workstation is to start with a generic workbench and more or less plunk down the equipment, materials, and tools needed to do the job. A workbench like this can be fine in some settings, like a maintenance shop where a variety of different tasks are performed on different types of items. However, when the work involves high-volume production, intricate tasks, or specialized operations, the traditional approach can create hindrances that waste time, lead to defects, and even create long-term disorders like back injuries or shoulder problems. It is normally better to design a specialized workstation in these circumstances. The first rule of design — form follows function — applies.  Understand the task and then design for that.

Applying the principles: Workstations

Unfriendly3 Force Clearance
Working position Force Clearance
You must understand the basic principles of human-friendly design to evaluate or design a workstation. Common issues and applications include:
  • Working position: Awkward positions that reduce efficiency and accuracy of work, plus increase fatigue and strain on the employee, including: Working with a bent or twisted back, elbows away from the body, bent or twisted wrists, bent neck.
  • Force: Exertion needed to handle materials and use tools.
  • Height and reach: In this context, these issues are often the root cause of awkward positions.
  • Motions: Excessive motions to handle materials and operate equipment.
  • Fatigue: Constant bending, reaching out with the arms, and gripping materials.
  • Pressure points: Hard edges, such as front of work surface or other protrusions.
  • Clearance: Sufficient room especially for legs and knees.
  • Environmental: Quality of lighting, temperature extremes, etc.

Steps

Step 1 — Define the optimal height and orientation

 
Magician
Pretend you can levitate the work to the perfect position
The first step, which is the one most often neglected, is to understand the optimal orientation for the product relative to the employee who does the work. Sometimes the best position for the product is horizontal, but more commonly a product is best accessed when it is on a slant. Likewise, sometimes the product can stay in the same orientation for all the steps of the job, but more commonly different tasks are best done with the product in a different orientation, especially when the product is complex.   It may not be feasible to provide optimal orientation for each and every step of a job. However, knowing how the product can best be positioned provides critical design objectives. If you don't know what you're aiming for, you can end up creating a workstation that contains inadvertent barriers to production and quality, and in addition causes wear-and-tear injuries among employees. Consequently, for each step of the job, ask these questions:
  • Access — Can employees access what they need in order to do the job efficiently?
  • Visibility — Is it possible to see what they need?
  • Working position — Will employees be in the optimal working position to do the work?
As you start out, do not be overly concerned about how to actually support or move the item — that comes next. The point here is to define the ideal height and orientation to do the work: if you could do anything you wanted, where should the work be? To help you answer these questions, consider the following:
  • Assume you have supernatural powers and can manipulate the product in the air with mental telepathy. Envision what you need to do. Think through all the different orientations that are possible and the logical implications of each.
  • Create a mock workstation with a highly adjustable test fixture for the item you're working on. You (and others) can work at this station and test different orientations to help identify the best positions.
  • Watch videotapes of the work as it is being performed. It is common to see things on a video that you don't see in the workplace, especially if you watch the video clip several times in succession. The difficulties that people have when doing the job help you determine how best to position the work. It can be very helpful to involve employees and supervisors in this process.

Step 2 — Identify a fixture or holder

Fixture1 Fixture2 Fixture3
Fixtures, simple and complex
Once you understand the optimal height and orientation of your specific situation, then turn to the practicality of how to achieve it. It could be a type of bench top fixture, a floor fixture, a conveyor workstation, or anything that you can envision. You may need height adjustment. If you need a work surface, the surface size may be smaller than you think, or it might be a slanted surface. Surprisingly, you may not need an actual surface at all. You may need to brainstorm a bit (or a lot, depending upon the circumstances). The purpose for providing the various options in the linked pages is to help you think outside the box. You want to make sure you identify what works best for the situation, rather than what is familiar.

Step 3 — Determine material handling requirements

Parts1 Parts2 Parts3
Parts handling, small and large
Determine requirements and options for parts movement at the workstation. Consider parts movements within the individual workstation and between workstations, including loading and unloading methods, parts presenters, and height relationships within the equipment. Your goal is to minimize the time and effort needed to move items around. Equalizing heights can be especially be helpful, since it may allow you to slide materials from place to place, rather than picking them up. (See also How to improve manual material handling and the Material handling knowledge base.)

Step 4 — Define tool and material needs and their location

Tools1 Tools2 Tools3
What tools and where?
What tools and materials do you need to do the job? What workstation layout do you need so that each item is handy? What storage features right at the workstation do you need, i.e. supports, holders, racks, etc.? You need to define a place for everything and make sure it is in the right place. (See also How to optimize hand tool use and the Hand tool knowledge base).

Step 5 — Review other issues for applicability:

Review1 Review2 Review3 Review4
Lighting Surface Seating Flooring
The final step involves reviewing of series of other ergonomics issues. These issues can usually be addressed in any order, in contrast to the above four steps, which should be done in sequence. Evaluate each of these topics as appropriate for your task: Visual access is part of Step 1 for the item being worked on, but can include other parts of the workstation such as dials and computer monitors. The question is if what you need to see is in your line of sight. Lighting is closely related to visual access, but has to do with issues like darkness and glare rather than line of sight. Magnification is again related to visual access, but the question is whether it would be helpful to enlarge the view of items. Arm supports may be needed to provide proper support for the arms and hands in certain tasks. Surface material — depending on the task, different types of surface material can be helpful: slippery, high friction, non-glare, etc. Clearance is needed for your arms, legs, and other parts of the body. Additionally, there must be room for tools, headgear, gloves, and similar items that are used. Sit-stand — in stationary jobs, it is best to alternate between sitting and standing, rather than doing either all day long. A range of techniques is available. Seating is obviously important for certain types of work. Flooring issues are equally important for standing work. Standing platforms are sometimes needed to raise people up to a better work height. Footrests can be beneficial — and critical in some situations — whether sitting or standing.

Point: Summary of design process

In sum, start by defining the optimal orientation of the product and the best fixture needed to enable this orientation. Then move "outward" to how the materials are moved in and out of the fixture, then to the tools and storage items, and then to the other aspects of the workstation. Everything is based on the ability of the employee to do the job well, with minimal time and effort.

Workstation case examples

Example1 Example2 Example3 Example4
Unique potter's wheel workstation Highly adjustable pedestal workstation Electronics workstation Workstation made from die cart

From workstation to production line

A production line is essentially a sequence of workstations that are connected one way or another. Consequently to set up a production line, you basically repeat this process multiple times. The challenge is when different tasks are best done in different heights and orientations. The workstations must then be set up to be integrated with material handling systems.

Conveyors

Examples of how a moving conveyor line can be adapted for different heights and orientations are found in the introduction (evolution of the assembly line: auto assembly and ham boning.) See also the conveyor workstation for more issues and best practices.

Carts and casters

AdjustableCart Trunnion PortablePositioner
Adjustable cart Trunnion on wheels Portable work positioner
An alternative to conveyors is to use carts and free-standing fixtures. With the right features, these techniques combine the ability to change orientation with moving the product down a production line. Combining the ability to change orientation of a product as it moves down a line may require some creative thinking. However, there is no limit to the types of production lines that can be  created. Next How to improve the machine-operator interface →


pingdom-test-string