Tasks (T) such as repair jobs on a telecommunications system, that are to be performed by a plurality of resources such as field engineers (E), at different locations in a geographical area (2), are scheduled by means of a scheduler (10) at a work manager server (5). The scheduler provides schedule data (11) corresponding to schedules of the tasks that individual ones of the resources are to carry out, from task data (4) concerning the tasks to be carried out and resource data (6) concerning characteristics of resources available to carry out the tasks over a given period. The scheduled tasks are provided with associated contingency values (C) which are each computed as a function of the difference between the time that a task is scheduled to start and the latest start time that is feasible for the task . The schedule data (11) is downloaded to a workstation (7). The downloaded data is displayed on a Gantt Chart and the task blocks on the display are colour coded according to their contingency values (C) to give a visual indication of their values.