Chapter 2 The.Design.of.Workstation.Furniture
2.6. Summary
Despite the fact that many brochures try to assure purchasers that their workstation furniture will accommodate many different users, as well as meeting any legal obligations, many desks fail from a usability/functionality perspective once introduced into a real working environment.
Fixed-height desks, if used in conjunction with fully adjustable chairs, are perfectly acceptable for use in an office.
The only individuals who may have difficulty in using fixed-height desks are very tall or short people and people with specific disabilities. As long as short people are provided with suitable adjustable chairs, they too should be able to use standard fixed-height desks.
Tall individuals need adjustments to their desks in the form of either retrofit attachments to increase the leg length of the desk or an alternative desk design, possibly a height-adjustable desk.
Height-adjustable desks come in various forms. They can have telescopic legs that can be extended; they can have a crank handle that is rotated to raise or lower the desk; or they can be electrically powered and adjusted using a small panel embedded in the desk surface.
Features on the undersurface of the desk should not compromise an indi- vidual’s sitting position.
One of most important features of the desk is the surface area available. It should be sufficient to allow users to arrange their screens and keyboards one in front of the other and directly in front of them.
The depth of the desk should be sufficient to allow users to position the screen about fingertip distance away from them when in their at-work position.
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The screen should not be positioned to one side of the seated operator so that it causes them to rotate their head to look at it or to twist their upper body. The user should always be able to sit directly in front of the screen and keyboard when they are in use.
The styling of worksurfaces should not compromise the way in which an individual works. Care should be taken that the worksurface styling allows the equipment to be laid out correctly and should permit the user to adopt a comfortable working posture.
The desk surface needs to be big enough to accommodate the mouse, documents, copy stand, and telephone if in use.
Desks should undergo properly managed trials before decisions are made about their purchase and introduction to the workplace to ensure that they suit the individuals and the task being performed.
Leading edges on desks should be rounded or bull-nosed to prevent com- pression of tissue in the wrist area.
The layout of the worksurface should be such that all items used for extended periods or regularly fall within the normal work area which means within easy reach. Items used on an irregular or infrequent basis can be stored in the zone of convenient reach which can be reached with a fully extended arm.
Items should not be stored on the floor around the seated user as this will require stooping or twisting to reach towards them. Such users should be provided with either a larger surface area or a trolley to accommodate the overflow.
The undersurface of the desk, both front to back and side to side, should allow users to move their legs freely and change position without hindrance.
The location of drawers should be carefully considered so that they do not limit the control users have over where they sit at a desk.
Cable management should be easy to use so that it does not discourage people from storing cables in the management system after desks have been moved around the office or equipment has been repositioned. Cables should not lie around the user’s feet.
Full consideration of task demands should be made before partitioning is introduced, as well as the likely impact on the psycho-social element.
Partitions can result in isolation and can have a negative impact on group cohesion.
Partitioning is most suited to jobs requiring confidentiality or to individuals who use the phone frequently which may distract other workers.
Computer users should not be required to sit on anything other than a fully adjustable chair when working.
The chair should be adjustable for height.
The backrest should be adjustable for tilt.
The lumbar support on the backrest should be capable of being repositioned relative to the lumbar area of the seated user.
The chair should have a five-star base on casters.
The chair should have sufficient padding to ensure the user is comfortable.
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The Design of Workstation Furniture 31 High backrests and head supports on chairs are not an absolute necessity and careful consideration should be given to whether they are required before they are introduced.
Head supports are usable only when the head is rested on their surface and this makes reference to the screen more difficult.
Care should be taken that smaller users have not been provided with chairs so large that they find it difficult to sit back against the backrest.
Armrests on a chair should not cause an obstruction when the user tries to sit close to the leading edge of the desk.
Users should not lower their chairs in order to get their armrests under the desk so they can sit closer to the work surface. This will cause them to sit too low relative to the desk and keyboard.
Problematic armrests should be removed.
Ideally, armrests should have a degree of adjustability both for height and width settings.
Any adjustment mechanism on a chair should be easy to use from a seated position. Any adjustment that requires the user to stand up or is complex will not be used properly, making it unlikely that the user will adopt an appropriate sitting position.
Users should be given thorough training in the use of their chairs, the adop- tion of appropriate working postures and how to use their workstations.
Footrests should be given only to users whose feet do not touch the floor once they have adjusted the height of their chairs.
A footrest needs to have a large surface area; it needs to be covered in non- slip material; and ideally, it should be height- and tilt-adjustable.
Users should not lower their chairs to get their feet on the floor. This causes the height of the keyboard and desk to rise relative to their seated position and forces them to work with their arms raised.
If wristrests are provided for use in front of the keyboard, users should be advised not to lean on these while they are keying. This will cause them to overextend their fingers.
Copy stands should be provided for individuals who work from documents while interacting with the computer. The stand should present the docu- ments at the same height and distance as the screen.
The screen should be set at a height suitable for each individual who might sit at the desk. The most effective way of doing this is by using either an articulating arm or building-block style platforms.
Individual who are required to make lengthy or regular phone calls should be provided with headsets. They should not clamp the handset of a tele- phone between shoulder and ear.
Individuals involved in lengthy periods of reading or writing should be pro- vided with a slope that raises the documents up towards them. This will eliminate the need to bend forward.
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3 Workstation Trials
3.1 IntroductIon
Many an organization has wasted significant money by investing in inappropri- ate or poorly designed workstation furniture. Glossy brochures sell the idea that the furniture will meet every possible need that an employer might have. Office furniture showrooms present a pristine environment filled with shiny new desks and attractive chairs. In both cases, the superficial qualities of the equipment can have an immediate impact on decision making. Unfortunately, decisions made on the basis of a few minutes of viewing or testing will not provide a clear indication of how successful that equipment might be once used in a real work environment. Getting a true appreciation of the likely success of any piece of equipment—whether a desk, chair, footrest, document holder, or anything else—is possible only after the equip- ment has been used during the performance of normal work in the real environment.
This illustrates the importance of having equipment on trial before committing to purchasing it, particularly if large numbers are involved.
If trials are to yield helpful information they need to be designed and managed carefully so that usable feedback can be collected. The feedback is the means by which an organization will identify accurately whether selected equipment is suit- able for the work being performed and whether the workers actually like it.
Trials can last a number of hours, several days, or even weeks. The duration and complexity of the trial is very much reliant on the nature of the equipment on trial, its likely impact once introduced into the working environment and the number of individuals who might use the equipment. For instance, a reading slope intended to be employed by one person might be used on a trial basis by the intended user for just a few hours. In contrast, an organization undertaking refurbishment may intend to introduce new desks and chairs for 800 employees, which would require a much more involved process of selection, short-listing and trialing.
Before starting the process of selecting furniture to include in a trial, the indi- vidual given responsibility for drawing up the shortlist should be in a position that ensures a complete understanding of what the users’ tasks entail and what those users need to complete their tasks accurately, efficiently, safely, and comfortably.
The trial manager should then prepare a list of requirements to offer potential equip- ment suppliers.
Some of the methods for generating an understanding of what the users’ work involves include direct discussions with the individuals performing the work and their managers or team leaders, reading job descriptions or standard operating procedures, conducting surveys and conducting a task analysis.
3.2 task analysIs
A task analysis is a formal method for both describing and analyzing the performance demands placed on an individual within the working environment. It is distinct from a job analysis which provides a breakdown of the activities, on a more general level, performed by a particular individual within an organization. A job analysis usually takes the form of a list of activities, duties, or responsibilities associated with the particular role under scrutiny. As part of the process of task analysis, complete tasks are systematically broken down into components and subcomponents; the result is referred to as the “task description.” This can be achieved successfully only by observing a skilled individual over an extended period while recording each activity/movement.
At the end of the analysis a profile will have been generated that specifies (1) the task requirements, such as operating the keyboard (possibly differentiating between alpha and numeric work), using the mouse, answering the telephone, reading docu- ments, using a pen, and so on; (2) the task environment, such as operating the mouse on the desk surface; and (3) the task behavior, which provides insight into how the user is working—for example, reaching across the desk to the mouse or holding a pen in the hand while inputting numerical data. Task behavior is influenced by previous experiences and training and limited by psychological and physiological factors (Stammers and Shepherd 1995).
In addition to specifying exactly what the individual’s tasks involve, the task analysis provides a structured breakdown of how long is spent on each component or subcomponent and what percentage of the overall task that aspect represents. One goal of this process is to enable the employer to identify the priorities in the task by recording either what element of the task is performed for the longest period of time or which element of the task is performed most often throughout the working period. By carrying out this procedure, the employer will get a profile of what any new workstation furniture has to achieve in terms of enabling users to complete their work effectively and efficiently. Also, developing a methodical sequence of task demands enables employers to compare the sequence with what is already known about human capabilities. This process allows them to identify inefficiencies in the current work—inefficiencies in this context meaning ergonomic inefficiencies where the user is working in a manner that is not ideal. For example, the task analysis may highlight that a significant feature of the work is telephone answering. Reference to the desk layout may reveal that the telephone is located at the most distant point on the desk which results in repeated reaching as the user picks up the handset. In addition to highlighting the poor workstation layout, the task analysis might pinpoint the need for a headset as an alternative to holding the handset of the telephone to the ear repeatedly for extended periods.
The task analysis can also aid in identifying the skills required to complete the tasks successfully or, perhaps, the training needed to develop the skills. Obviously, to provide such information the task analysis should be thorough and include all components and subcomponents of the tasks. This underlines the importance of taking the time to generate a thorough task description prior to starting the analysis.
The description details the step-by-step actions and movements involved in the operation being observed.
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3.2.1 Starting the Procedure
At the outset of the task analysis process, there should be agreement on what the analysis should achieve. This will allow decisions to be made about how the analysis will be carried out. For instance, how many individuals will be observed, and how many at what level within the organization? To establish exactly who would be con- sidered representative of the organization’s working population, the appropriate personnel with access to this information should be involved in the decision-making and planning process from an early stage. The users who will be the focus of the observations need to be informed about the process and confirmation needs to be given that each relevant individual will be available in the specific period when the task analysis is to be carried out. Consideration has to be given to the fact that even individuals identified as performing identical tasks may actually perform them dif- ferently because of personal preferences and this may have an impact on the results of the analysis.
Having established the aims of the task analysis at the outset of the process, those compiling the data will be able to collect information that is directly relevant to the project’s aims. To maintain this, they also need to ensure that they detail the task components that make up the task description accurately. This suggests that cross-referencing with other individuals performing the same task is advisable.
Consideration should be given to whether more than one type of operation is performed at the workstation at different times. For instance, an individual might perform dedicated screen-based operations on some days but clerical duties on other days. Attention needs to be paid to whether more than one operator will use the same workstation during a 24-hour cycle, as with a multiple shift system in a call center.
Steps need to be taken to ensure that a representative sample is covered during the analysis. If particular tasks cannot be observed for practical reasons, efforts should be made to ensure that these do not contain elements likely to undermine the findings of the actual observations. This can be achieved through discussions with relevant personnel and with reference to any documentation that records details relating to the tasks.
Decisions have to be made prior to commencing the analysis about whether the individual carrying out the observations will interrupt the worker being observed to clarify points or whether they will wait until the end of the observations and then carry out a “debriefing” session. In the former case, the operation can be performed and observed in real time, which offers a more realistic view of the demands placed on the individual. In the latter case, debriefing should be carried out soon after the observations have ceased to avoid any effects resulting from delayed information recall by the worker.
If task descriptions—the list of individual components making up the overall task’s demands—are being developed on the basis of documentation such as job descriptions or training materials, it should be kept in mind that these documents may not record every step in a sequence of steps; they may not provide sufficient detail to allow for a proper analysis; the contents may include ambiguous wording; or the writer may have made a number of erroneous assumptions about the operation. In addition, the contents of the documents may be out of date even though the document
itself has been produced quite recently, perhaps because the document was based on information that was collated some time before the document’s creation.
Task descriptions can be generated through discussions with personnel, either through formal or informal conversations with individuals or by administering a questionnaire. Care should be taken to select the personnel who are likely to offer the most accurate information relating to the task demands. That is not to say that only experienced employees should be involved in this process. Long-term employees may have developed working practices that would not be deemed appropriate and would not be advisable to perpetuate, even though they themselves may perceive their own working practices as “normal” and acceptable. Clearly, designing and selecting a workstation to accommodate poor working practices would not be an advisable strategy.
3.2.2 information collection
The driving force behind the observations should be that all information collected will address the issues of concern. Those collecting the information should not be open to criticism that they were biased in the sense that they focused only on task features that they considered important. A record should be made of exactly what has been observed, in what environment, with what equipment, and who was per- forming the task. Creating formal records contributes to the development of an audit trail that later could become important in illustrating how purchasing decisions were made and the rationale behind them.
During the course of the data collection, if the analyst identifies any conflicts in terms of how they understand the task should be completed, having read documented explanations, and what they are observing, they should inquire why such conflicts are apparent. If the session is being timed, the questions should wait until the session is over so that the user is not interrupted. To avoid any confusion or conflicts during the actual data collection, it is always useful for the analyst to observe an untimed run-through of the task during which queries can be addressed.
If an individual is describing a task during its execution as a means to expand on the data collected by the analyst, the worker may need to be encouraged to offer sufficient detail about actions and movements. To facilitate this, the worker should be given an explanation of the purpose behind the task analysis. The analyst needs to be alert to the fact that the worker may, during the description of the task, move away from the focus of the analysis and start to discuss unrelated or irrelevant topics.
Alternatively, if the analyst becomes aware that the user is reluctant to describe the tasks or becomes hesitant during the discussions, the analyst should investigate this.
Group discussions might give individual users more confidence when providing information. However, care needs to be taken that senior members in the group do not monopolize the discussions.
When the actual observations are being carried out, it is quite useful to make a video recording of the operations as well as observing directly. This allows clarifi- cation of details at a later point and avoids the need to request the user to repeat an operation or movement. Many people, however, become self-conscious when being videoed and this may have an effect on performance. For that reason, it is advisable