Evaluation of the usability of digital maintenance manuals developed without either user input or a task analysis

The primary objective was to investigate the value that can be added to a low-cost digital maintenance manual by the addition of a navigational aid. Two versions of a digital maintenance manual were developed, the difference between them being the number of design heuristics observed when designing navigational aids. Neither version was based on an analysis of the tasks carried out by users, nor were users involved in the design process. Instead, the manuals were developed directly from the digital information used to produce the existing paper manual. Usability trials were carried out to test both versions according to the time taken and errors committed by users during typical information retrieval tasks. Users were questioned to determine their ease of use (EOU) perceptions for each manual. The main outcomes were that the navigation aid used in the second version reduced the time taken to use the manual but increased the number of errors made by users. The navigational aid also seemed to reduce the perceived EOU compared with the first version. In both cases, the perceived EOU was lower than for a previous digital manual that had been developed using a task analysis and user input. The paper concludes by recommending the development of a generic task model of user interaction with digital maintenance manuals.