Denning Requirements

For the use of a large screen system in a control room, different factors have to be considered. These factors include the physical location of the large screen in the control room, with consideration for the available space and the nature and duration of visualisation and operation. Different considerations will prevail if the screen is to be used on a full-time (24/7) operational basis or part-time (for example, only during certain work shifts or usage patterns). Another consideration is the type and quality of displayed sources and, in particular, whether these will be from video or computer sources. In deciding the location of the screen, consideration needs to be given to the physical conditions in the control room, such as the lighting conditions (if the light source is artificial or natural) and the position of windows and skylights providing any natural lighting. Risk of glare is very important, as glare (for example, day­light reflection) could completely kill the visibility of the screen. Particular attention needs to be given to elements of the room construction, such as the weight-bearing capability of the floor and the construction of the walls. The technology of large screen displays requires certain environmental conditions, including a dust-free environment and a robust base construction that keeps the screen stable. Given that space is a critical issue, thought should be given to the position and number of access points for the control room operators. The number of operators and users at any one time is also an influencing factor, as this affects sight lines to the screen and the optimal location of other equipment that the operators may need. Overcrowding is to be avoided. It is also important to have a clear allocation of responsibility between the operators to prevent confusion and work duplication.

In terms of defining needs, there are many features of the large screen display that should be considered while planning the use of the technology and certainly before purchasing the equipment. The size of the large display screen and the space needed for its effective use should not be underestimated. The height of the room is also critical and needs to be factored into calculations, as does the height of sur­rounding furniture to be placed in the room. Consideration should be given to the distance that the operators are expected to be from the screen and whether their view is impeded by intervening furniture. The distance that the operators are from the dis­play cubes that make up the large display screen will affect the operators’ usability of the technology.

In terms of needs of the technology, the size and resolution of cubes in the dis­play are a key issue in the suitability of the equipment to the size of the room in which it is located and the ease with which the users can view the displayed data. Large display screens are available in curved and plane surface formats. The avail­able space overall and the location of the control room operators in relation to the screen display will be deciding factors in the choice of these formats. Other contrib­uting factors are the number and type of resources to be used in conjunction with the display screen.

When purchasing a large screen, natural areas of inquiry will include budget (especially any budgetary restrictions or constraints, such as those imposed by a head office on a regional operation). Apart from deciding the budget available for the equipment and including the projected costs of maintenance, it is wise to make a site visit to make a detailed inspection of the equipment in use. In this way the potential purchaser can see the actual dimensions of the equipment in the workplace. Included in budgetary issues are projected service and maintenance costs. Technical questions include the durability of the screen, the required resolution of the displayed sources, and the visibility and readability of the data and information displayed on the screen (given the location factors and the size of the room and number of users). Given Moore’s law[6] that technology improves exponentially every two years, it would be prudent to check the equipment for expandability for a later upgrade.