London Ambulance Service Failure

The capital of the United Kingdom Ambulance fiasco ? The London Ambulance Service (LAS) Computer Aided Despatch (CAD) dodging failed dramatic exclusivelyy on October 26th 1992 shortly after it was introduced The arrangement could not cope with the load placed on it by normal use The receipt to emergency calls was several hours Ambulance communications failed and ambulances were lost from the establishment. ? A series of errors were made in the procurement, design, implementation, and introduction of the system. Ian Sommerville 2004 computer software Engineering strip Studies Slide 1London Ambulance Service ? ? Managed by S come onh West Thames Regional Health Authority. Largest ambulance service in the world (LAS inquiry report) Covers geographical area of over 600 square miles resident population of 6. 8 million people (greater during daytime, especially central London) Carries over 5,000 patients every day 2,000-2,500 calls received daily, of which 1,3001,600 are emer gency calls. Ian Sommerville 2004 software package Engineering baptistry Studies Slide 2 Computer-aided despatch systems ? Provide one or more of the following Call taking Resource identification Resource militarisation Ambulance choice management. CAD software & hardware Gazetteer and mapping software Communications interface (RIFS). Radio system Mobile data terminals (MDTs) Automatic vehicle localization system (AVLS). ? Consist of Ian Sommerville 2004 Software Engineering Case Studies Slide 3 The manual system to be replaced ? Call taking Recorded on form location identified in map book forms sent to central collection point on conveyor belt Form collected passed onto resource allocator depending on region duplicates identified.Resource allocator decides on which resource to be mobilised recorded on form and passed to dispatcher Dispatcher telephones germane(predicate) ambulance station, or passes mobilisation instructions to radio operator if ambulance already on road ? Resource identification ? Resource mobilisation ? Whole process meant to take 3 minutes. Software Engineering Case Studies Slide 4 Ian Sommerville 2004 Concept/design of the CAD system ? Existing systems dismissed as inadequate and impossible to modify to incur LASs needs Intended functionality greater than available from any existing system.To consist of Computer Aided Dispatch Computer map pageant Automatic Vehicle Location System (AVLS) Must integrate with existing MDTs and RIFS (Radio Interface System). Near 100% accuracy and reliability of technology Absolute cooperation from all parties including CAC lag and ambulance crews. ? Desired system ? Success dependent upon Ian Sommerville 2004 Software Engineering Case Studies Slide 5 Problems Procurement (i) ? Contract had to be put start to open tender Regulations emphasis is on best price 35 companies expressed interest in providing all or part of the system just about raised concerns over the proposed timeta ble of less than 1 year until full implementation. ? Previous Arthur Andersen report largely ignored Recommended budget of ? 1. 5M and 19 month timetable for packaged solution. approximately(prenominal) estimates to be significantly increased if packaged solution not available Report never shown to new Director of Support Services. ? Only 1 out of 17 proposals met all of the project teams requirements, including budget of ? 1. 5M. Software Engineering Case Studies Slide 6 Ian Sommerville 2004 Problems Procurement (ii) ? Successful consortium Apricot, Systems Options (SO), Datatrak offer at ? 937k was ? 700k cheaper than the nearest bid SOs quote for the CAD development was altogether ? 35k Their previous development experience for the emergency services was only for administrative systems. Ambiguity over lead contractor. Systems theatre director Career ambulance man, not an IT professional, already told that he was to make way for a properly qualified systems manager Anal yst Contractor with 5 years experience working with LAS. ? 2 key members of evaluation team Ian Sommerville 2004Software Engineering Case Studies Slide 7 Problems Project management ? Lead contractor responsible Meant to be SO, but they quickly became snowed under, so LAS became more responsible by default No relevant experience at LAS or SO. ? ? Concerns raised at project meeting not followed-up. SO regularly late in delivering software Often too of suspect quality, with software changes put through on the fly. ? ? Formal, independent QA did not exist at any stage throughout the CAD system development. Meanwhile, various technical components of the system are failing regularly, and deadlines missed.Software Engineering Case Studies Slide 8 Ian Sommerville 2004 Problems Human resources & training (i) ? ? ? ? ? Generally positive situation to the introduction of new technology. Ambiguity over consultation of ambulance crews for development of original requirements. Circumstant ial evidence of resistance by crews to Datatrak equipment, and deliberate misleading of the system. Large happy chance in the midst of when crews and CAC staff were trained and implementation of the system. Inability of the CAC and ambulance staff to appreciate each others role Exacerbated by separate training sessions.Software Engineering Case Studies Slide 9 Ian Sommerville 2004 Problems Human resources & training (ii) ? ? ? ? ? ? ? Poor industrial relations. wariness fear of failure. CAD system seen as solution to managements desire to reduce outdated working practices. System allocated nearest resource, regardless of originating station. System removed flexibility in resource allocation. Lack of voice come to exacerbated them and us. Technical problems reduced confidence in the system for ambulance crews and CAC staff. Ian Sommerville 2004 Software Engineering Case Studies Slide 10 System problems Need for near improve information Without accurate knowledge of vehicle loc ations and status, the system could not allocate optimum resources. There were numerous possible reasons for incorrect information being passed sanction to the system. Numerous technical problems with the system, including Failure to identify all duplicated calls Lack of prioritisation of exception messages Exception messages and awaiting attention queues scroll off top of screen. ? Poor interface between crews, MDTs & the system ? Unreliability, slowness and operator interface Ian Sommerville 2004Software Engineering Case Studies Slide 11 Configuration changes ? Implementation of the system on 26 October voluminous a number of significant changes to CAC operation, in particular Re-configuring the control room Installing more CAD terminals and RIFS screens No paper backup system physically separating resource allocators from radio operators and exception rectifiers Going pan London rather than operating in 3 divisions Using only the system proposed resource allocation s Allowing some call takers to allocate resources Separate allocators for different call sources. Ian Sommerville 2004 Software Engineering Case Studies Slide 12 So, what happened? ? ? Changes to CAC operation made it extremely difficult for staff to intervene and correct the system. As a consequence, the system rapidly knew the correct location and status of fewer and fewer vehicles, leading to Poor, duplicated and delayed allocations A reconstruct up of exception messages and the awaiting attention list A slow up of the system as the messages and lists built up An increased number of call backs and wherefore delays in telephone answering. Ian Sommerville 2004Software Engineering Case Studies Slide 13 Why did it fail? ? Technically, the system did not fail on October 26th repartee times did become unacceptable, but overall the system did what it had been designed to do Failed 3 weeks later due to a program error this was a store leak where allocated memory was not comple tely released. Management Union System manager Government. ? It depends who you ask Ian Sommerville 2004 Software Engineering Case Studies Slide 14 Lessons in condition(p) ? Inquiry report makes detailed recommendations for future development of theLAS CAD system, including Focus on repairing reputation of CAD within the service Increasing sense of ownership for all stakeholders They still believe that a technological solution is required Development process must allow fully for consultation, quality assurance, testing, training Management and staff must have total, demonstrable, confidence in the reliability of the system Any new system should be introduced in a stepwise approach. Ian Sommerville 2004 Software Engineering Case Studies Slide 15