CASE REPORT: Due Date: 8th June, 2011. Structure: • Questions are given at the end. • Each answer should be at least of 1 page. • Explain in your own words. Evaluation: 10%
Information Systems Failure: The Case of Computer-Aided Dispatch (Cad) System at London Ambulance Service 1. Introduction The LAS covers a geographical area of just over 600 square miles and handles emergencies for a resident population of 6.8 million people. The CAD project is one of the most frequently quoted UK-based examples of information systems failure that took place in early 1990s. The prominence of this particular case is due to the ‘safety critical’ nature of this system and the claim that 20-30 people may have lost their lives as a result of CAD failure. 2. Description of the Manual Dispatch System The manual dispatch system consists of: a) call taking, b) resource identification, and c) resource mobilization. Call Taking: Emergency calls are received by ambulance control. Control assistants write down details of incidents on pre-printed forms. The location of each incident is identified and the reference co-ordinates are recorded on the forms. The forms are then placed on a conveyer belt which transports them to a central collection point. Resource Identification: Other members of ambulance control collect the forms, review the details on the forms and decide which resource allocator should deal with each incident. The resource allocator examines the forms for a particular sector, compares the details against information recorded for each vehicle and decides which resource should be mobilized. The status information on these forms is updated regularly from information received via the radio operator. The resource is recorded on the original form which is then passed on to a dispatcher. Resource mobilization: The dispatcher either telephones the nearest ambulance station or passes instructions to the radio operator if an ambulance is already mobile.
A number of problems exist with the manual dispatch system. Most problems are related to the time-consuming and error-prone nature of activities such as: identification of the precise location of an incident, the physical movement of paper forms, and maintaining up-to-date vehicle status information. Therefore, a Computer- Aided Dispatch (CAD) system was considered as a solution to overcome these problems. 3. The Computer-Aided Dispatch System 3.1 Purpose The objective of the CAD system was to automate many of the human-intensive processes involved in the manual despatch system. 3.2 How the CAD system was intended to work The essential features of the CAD system are shown in Figure 1 which illustrates how the system was intended to work in practice. British Telecom (BT) operators would route all 999 calls concerning medical emergencies to LAS headquarters. A total of 18 ‘receivers’ were then expected to record on the system the name, telephone number and address of the caller, and the name, destination address and brief details of the patient. This information would then be transmitted over a LAN to an ‘allocator’. The system would pinpoint the patient’s location on a map. The system was also expected to monitor continuously the location of every ambulance via radio messages transmitted by each vehicle. The system would then determine the nearest ambulance to the patient.
Figure 1: The structure of CAD system at LAS
Experienced ambulance ‘dispatchers’ were organized into teams based on three zones (south, north-east, and north-west). Dispatchers would be offered details of the three nearest ambulances by the system and the estimated time each would need to reach the scene. The dispatcher would choose an ambulance and send patient details to a small terminal screen located on the dashboard of the ambulance. The ambulance crew would then be expected to confirm that it was on its way. If the selected ambulance was in an ambulance depot then the...