Frame Relay - for Faster and More Efficient Data Communications ...

Fig. 9User interface for desk-top telephone setsThe advent of the display in desk-top telephoneshas solved many Human Factors problems and,at the same time, has created new ones. Initially,the type and quantity of information displayedwas specified and the way in which users accessedthe various functions and features wereidentified.Fig 9a illustrates the "Idle Mode" with informationsuch as time and date, subscribers' extensionnumber and subscriber name. The third rowis reserved for menu selection only. A maximumof four alternatives are presented, each correspondingto a menu key located directly underneath.Figure 9b represents the "Message Mode". Theuser is informed that there are messages andcan either call a person direct, leaf through othermessages or delete messagesReferences1 Dialogergonomi - Effektiv interaktionmanniskor-dator. Mekanforbundet 1989,Mekanresultat 89005 ISBN 91-524-1021-8.2 Asker, B.: Graphic User Interfaces. EricssonReview 67, (1990):3, pp 138-146.3 Brantberg, H., Ostman, J.: VDU Maps inSophisticated Craft. Ericsson Review 68(1991):1,pp 10-20.4 Lindhe, R. Wiklund J..Ericsson Design. -Policy, Guidelines and Methodology.Ericsson Review 66 (1989):1, pp 40-46.5 A Guide to Usability. 1990. The Open University,Milton Keynes, England.interface must work efficiently and beunderstood irrespective of whether it isused by a Russian or an Australian operator.Design of desk-top telephone setsThe desk-top telephone set has alwaysbeen the subject for Human Factors application.Traditionally, Human Factorshas addressed the physical issues, suchas numeric keyboard layout, keytopshape and size, receiver weight, size andbalance.With the advent of digital phones, the emphasishas shifted from these physical issuesover to the analysis of procedures requiredto obtain the wide variety offunctions and features now available.The procedures required to obtain thesefeatures/functions have been none toouser-friendly. The everyday user has hadto enter long unfamiliar codes, such as*21 * number #, in order to use the simple"follow-me" feature. The net result of theseawkward codes was that many of the features/functionsoffered were not used becauseprocedures were long and difficultto remember.The situation was partly remedied by increasingthe number of programmablekeys on the telephone set. Instead of thecomplicated codes, the user only neededto press one key. This was convenient forthe user but resulted in telephone sets witha vast number of keys, which was not particularlycost-efficient. The advent of thedisplay in the telephone set eased manyof the Human Factors problems mentioned.The aim was to minimise the useof long codes and reduce the number ofkeys. But the display created new problems.Human Factors work addresseduser-interface design, in particular the typeand quantity of information displayed andthe way in which the user accessed thevarious features/functions available. Onthe basis of this analysis, then and onlythen, could the size of the display be established.Figs 9a and 9b illustrate the informationcontent in the telephone display. The exemplifieddisplay is made up of three rowswith 40 characters in each row.The analysis of the user interface is followedby a visualisation process whereend users participate in the simulation andevaluation of traffic situations. User participationand feedback is an integral part ofthis design and development work.SummaryIn all development work there is a desireto improve user efficiency and technicalperformance and to rationalise production.In addition, products and systems are increasinglybeing combined into new, evenmore sophisticated and complex creations.For a market-orientated technical corporationlike Ericsson, the usability of its productsis an important part of the company'sbusiness and marketing strategy. It is vitalthat products and systems are designedso that they meet customers'requirementsand expectations.The Human Factors work contributes activelyto the usability, acceptability andlearnability of Ericsson products andsystems, and to the application of thecompany's Human Factors policy withinthe scope of the Ericsson Human Factorsprogramme.ERICSSON REVIEW No. 1-2, 1992