Diary studies as a macro-ergonomic evaluation tool: Development of a shift diary and its application in ergonomic evaluations

A diary instrument that could be used as a macro-ergonomic evaluation tool was developed and applied to evaluating monitoring tasks. In the first part of the study, the development of the instrument allowing the measurement of employee evaluations of perceived workload, attained performance, and strain is presented. Railway signalers and controllers filled out a diary every four hours over ten consecutive working shifts. Analysis of the objective workload conditions of the railway signalers and their relations to subjective workload perceptions in the diary indicates a satisfying validity of the measures. In the second part of the study, the newly developed diary instrument was used for macro-ergonomic evaluations in two other controller work places. Using the shift diary it was possible to answer practical macro-ergonomic questions that originated from the respective work situations. The strengths and possible limitations of the diary instrument are discussed.