London Ambulance Service Failure

The capital of the United Kingdom Ambulance fiasco ? The London Ambulance Service (LAS) figurer Aided Despatch (CAD) form failed dramatically on October 26th 1992 shortly after it was introduced The agreement could non cope with the load placed on it by normal exercising The response to emergency calls was several hours Ambulance communications failed and ambulances were lost from the dodging. ? A series of errors were made in the procurement, design, implementation, and introduction of the remains. Ian Sommerville 2004 Softw atomic consequence 18 technology slip of paper Studies slide 1London Ambulance Service ? ? Managed by S byh West Thames regional Health Authority. Largest ambulance service in the world (LAS inquiry report) Covers geographical rural area of over 600 square miles Resident population of 6. 8 million mass (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 emergency calls. Ian Sommerville 2004 Software plan Case Studies dislocate 2 Computer-aided payload dodges ? Provide one or to a greater extent of the following Call winning Resource identification Resource mobilisation Ambulance election management. CAD packet & hardware Gazetteer and mapping software frame Communications interface (RIFS). Radio system Mobile data terminals (MDTs) Automatic vehicle placement system (AVLS). ? inhabit 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 assembly point on conveyor belt Form collected passed onto choice allocator depending on region duplicates identified.Resource allocator decides on which imaging to be mobilised recorded on form and passed to dispatcher Dispatcher telephones applicable ambulance station, or passes mobilisation instructions to radio hooker if ambulance already on road ? Resource identification ? Resource mobilisation ? Whole mathematical 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 meet LASs needs mean functionality greater than available from any existing system.To consist of Computer Aided Dispatch Computer map display Automatic fomite Location System (AVLS) Must integrate with existing MDTs and RIFS (Radio Interface System). tightfitting 100% accuracy and reliability of technology Absolute cooperation from all parties including CAC rung 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 out to open tender Regulations emphasis is on best price 35 companies expressed interest in providing all or part of the system Most raised concerns over the pro posed timetable of less than 1 year until all-embracing implementation. ? Previous Arthur Andersen report largely ignored Recommended budget of ? 1. 5M and 19 calendar month timetable for packaged root. Both estimates to be significantly change magnitude if packaged solution non available Report never shown to new Director of hold up Services. ? Only 1 out of 17 proposals met all of the get word police squads 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 machinate at ? 937k was ? 700k cheaper than the nearest bid SOs quote for the CAD development was only ? 35k Their previous(prenominal) development experience for the emergency services was only for administrative systems. equivocalness over lead contractor. Systems manager Career ambulance man, not an IT professional, already told that he was to make way for a properly q ualified systems manager analyst Contractor with 5 years experience working with LAS. ? 2 learn 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 also of suspect quality, with software changes put through on the fly. ? ? Formal, independent QA did not exist at any correspond 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 gracious resources & discipline (i) ? ? ? ? ? Generally positive attitude to the introduction of new technology. ambiguity over consultation of ambulance crews for de velopment of original requirements. Circumstantial evidence of bulwark by crews to Datatrak equipment, and deliberate misleading of the system. Large gap between when crews and CAC round were trained and implementation of the system. Inability of the CAC and ambulance staff to appreciate each others character Exacerbated by separate training sessions.Software Engineering Case Studies Slide 9 Ian Sommerville 2004 Problems Human resources & training (ii) ? ? ? ? ? ? ? Poor industrial relations. Management care of failure. CAD system seen as solution to managements desire to reduce outdated working practices. System allocated nearest resource, careless(predicate) of originating station. System removed flexibility in resource allocation. Lack of persona contact 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 perfect informa tion Without accurate knowledge of vehicle locations and status, the system could not allocate optimum resources. There were numerous possible reasons for amiss(p) information being passed back to the system. Numerous technical problems with the system, including Failure to site all duplicated calls Lack of prioritisation of exception messages Exception messages and awaiting attention queues scroll away top of screen. ? Poor interface between crews, MDTs & the system ? Unreliability, slowness and operator interface Ian Sommerville 2004Software Engineering Case Studies Slide 11 course changes ? Implementation of the system on 26 October involved 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 direct in 3 divisions Using only the syste m proposed resource allocations Allowing around 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 tricky for staff to intervene and correct the system. As a consequence, the system chop-chop knew the correct location and status of fewer and fewer vehicles, leading to Poor, duplicated and slow up allocations A build 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 hence 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 Response times did become unacceptable, but overall the system did what it had been designed to do Failed 3 weeks later imputable to a program error this was a entrepot leak where allocated memory was not completely released. Management Union System manager Government. ? It depends who you entreat Ian Sommerville 2004 Software Engineering Case Studies Slide 14 Lessons learned ? dubiousness report makes detailed recommendations for future development of theLAS CAD system, including Focus on repairing reputation of CAD within the service Increasing sense of self-will for all stakeholders They still believe that a technological solution is take 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