Since 1976 the author has worked with L. M. Ericsson Ab of
Stockholm, Sweden, providing ergonomics advice relating to the design
of operator positions for stored program controlled telephone exchanges
manufactured by this company. The research was I performed in three
phases: a literature review, preliminary experiments to evaluate
alternative equipment designs and finally a series of trials of the
prototype under simulated call conditions.
The basis of the new operator position is tie provision of a
computer terminal, consisting of a datascreen or video display unit
(vdu) and keyboard at each operator desk. These terminals enable the
operator to enter call details into memory stores from which they can
be 'read' by the computer, displayed at any operator position or routed
to the charging system. By eliminating many repetitious and error
prone number entries, by abolishing pager handling tasks completely
and by automating certain call handling operations a more efficient and
effective service can be provided to subscribers.
The literature review report, produced on completion of Phase I,
summarised the ergonomics research relating to datascreens, keyboards,
dialogues, workstations and environmental factors. As a result of the
review the author was able to produce detailed ergonomics recommendations
for many parts of the system.
Phase II consisted of a programme of experiments to provide the
data required to resolve design conflicts remaining at the conclusion
of Phase I. In successive stages a panel of experts reduced the
potential number of datascreen designs to practicable numbers for
controlled experiments. These datascreens, filters and screen treatments
were systematically compared in experiments and a suitable design
was selected. In Phase III an experiment was conducted to evaluate the entire
operator position under simulated call handling conditions. In
addition to collecting objective measures of call handling speed and
accuracy, the experiments also enabled visual fatigue to be
assessed and call handling equipment and procedures to be judged
by experienced operators under' reasonably realistic conditions.