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... d 27 November 1992, was, like all major failures, blamed on a number of factors. These include inadequate training given to the operators, commercial pressures, no backup procedure, no consideration was given to system overload, poor user interface, not a proper fit between software and hardware and not enough system testing being carried out before hand. Claims were later made in the press that up to 20 - 30 people might have died as a result of ambulances arriving too late on the scene. According to Flowers, "The major objective of the London Ambulance Service Computer Aided Despatch (LASCAD) project was to automate many of the human-intensive processes of manual despatch systems associated with ambulance services in the UK. Such a manual system would typically consist of, among others, the following functions: Call taking.
Emergency calls are received by ambulance control. Control assistants write down details of incidents on pre-printed forms. " The LAS offered a contract for this system and wanted it to be up and running by 8 th January 1992. All the contractors raised concerns about the short amount of time available but the LAS said that this was non-negotiable. A consortium consisting of Apricot, Systems Options and Data trak won the contract. Questions were later asked about why there contract was significantly cheaper than their competitors. (They asked for 1. 1 million to carry out the project while their competitors asked for somewhere in the region of 8 million. ) The system was lightly loaded at start-up on 26 October 1992.
Staff could manually correct any problems, caused particularly by the communications systems such as ambulance crews pressing the wrong buttons. However, as the number of calls increased, a build up of emergencies accumulated. This had a knock-on effect in that the system made incorrect allocations on the basis of the information it had. This led to more than one ambulance being sent to the same incident, or the closest vehicle was not chosen for the emergency. As a consequence, the system had fewer ambulance resources to use. With so many problems the LASCAD generated exception messages for those incidents for which it had received incorrect status information.
The number of exception messages appears to have increased to such an extent the staff were not able to clear the queues. Operators later said this was because the messages scrolled of the screen and there was no way to scroll back through the list of calls to ensure that a vehicle had been dispatched. This all resulted in a viscous circle with the waiting times for ambulances increasing. The operators also became bogged down in calls from frustrated patients who started to fill the lines. This led to the operators becoming frustrated, which in turn led to an increased number of instances where crews failed to press the right buttons, or took a different vehicle to an incident than that suggested by the system. Crew frustration also seems to have contributed to a greater volume of voice radio traffic.
This in turn contributed to the rising radio communications bottleneck, which caused a general slowing down in radio communications which, in turn, fed back into increasing crew frustration. The system therefore appears to have been in a vicious circle of cause and effect. One distraught ambulance driver was interviewed and recounted that the police are saying "Nice of you to turn up" and other things. At 23: 00 on October 28 the LAS eventually instigated a backup procedure, after the death of at least 20 patients. An inquiry was carried out into this disaster at the LAS and a report was released in February 1993. Here is what the main summary of the report said: "What is clear from the Inquiry Team's investigations is that neither the Computer Aided Despatch (CAD) system itself, nor its users, were ready for full implementation on 26 October 1992.
The CAD software was not complete, not properly tuned, and not fully tested. The resilience of the hardware under a full load had not been tested. The fall back option to the second file server had certainly not been tested. There were outstanding problems with data transmission to and from the mobile data terminals. Staff, both within Central Ambulance Control (CAC) and ambulance crews, had no confidence in the system and was not all fully trained and there was no paper backup. There had been no attempt to foresee fully the effect of inaccurate or incomplete data available to the system (late status reporting / vehicle locations etc. ).
These imperfections led to an increase in the number of exception messages that would have to be dealt with and which in turn would lead to more call-backs and enquiries. In particular the decision on that day to use only the computer generated resource allocations (which were proven to be less than 100 % reliable) was a high-risk move. " In a report by Simpson (1994) she claimed that the software for the system was written in Visual Basic and was run in a Windows operating system. This decision itself was a fundamental flaw in the design. "The result was an interface that was so slow in operation that users attempted to speed up the system by opening every application they would need at the start of their shift, and then using the Windows multi-tasking environment to move between them as required. This highly memory-intensive method of working would have had the effect of reducing system performance still further. " The system was never tested properly and nor was their any feedback gathered from the operators before hand. The report refers to the software as being incomplete and unstable, with the back up system being totally untested.
The report does say that there was "functional and maximum load testing" throughout the project. However it raised doubts over the "completeness and quality of the systems testing." It also questions the suitability of the operating system chosen. This along with the poor staff training was identified to be the main root of the problem. The management staff was highly criticised in the report for their part in the organisation of staff training. The ambulance crew and the central control crew staff were, among other things, trained in separate rooms, which did not lead to a proper working relationship between the pair. Here is what the report said about staff training: "Much of the training was carried out well in advance of the originally planned implementation date and hence there was a significant "skills decay" between then and when staff were eventually required to use the system.
There was also doubts over the quality of training provided, whether by Systems Options or by LAS's own Work Based Trainers (WBTs). This training was not always comprehensive and was often inconsistent. The problems were exacerbated by the constant changes being made to the system. " Facts are taken from web web and the report of the Inquiry into the London Ambulance Service, February 1993. 2. 5 Poor user-interface The last case was a good example of how a poor user-interface can lead to mayhem. Another similar case was reported to the Providence newspaper. The Providence (part of New York) police chief, Walter Clark, was grilled over why his officers were taking so long to respond to calls. In one case it took two hours to respond to a burglary in progress.
He explained that all the calls are entered into a computer and are shown on a monitor. However the monitor can only show twenty reports at a time as the programmer did not design a scroll function for the screen. The programmer had some serious misconceptions about the crime rate in New York. Facts taken from: web 2. 6 Over reliance on the software system The Exxon Valdez oil disaster was simultaneously blamed on the drunken captain, the severely fatigued third mate, the helmsman and the "system." The system refers to the auto-pilot of the ship and the lack of care the crew had on its operation.
According to Neumann the crew were so tired that they did not realise that the auto-pilot was left on and so the ship was ignoring their rudder adjustments. This example shows that even though everything was working properly, all the safety measures had a minimal effect when they were trying to override the auto-pilot. This is a very small mistake and could easily have been prevented. The There- 25 case, a system designed to give the right amount of radiation to the patient in chemotherapy treatment also fell into a case "foolproofedness." The operators did not imagine the "software permitted the therapeutic radiation device to be configured unsafely in X-Ray mode, without its protective filter in place" (Neumann). Such blind faith in the system resulted in several patients being given too high a dose that killed the patients. 3. 0 Conclusion It is obvious to see from these examples that failures are very rarely due to one cause alone. In major system failures it can be over a dozen mistakes being made that usually results in the failure of the system.
Also the mistakes have a domino effect or leads to a viscous circle of mistakes, the systems becoming worse and worse during both the design and implementation stage. In almost all large system failures there is a case of when commercial pressures are put above safety. The Paddington rail crash (5 th October 1999) could have been prevented if the train had been fitted with the Train Protection Warning System. This system would physically stop the train if it went through a red signal and was recommended in the report following the train crash at Southall. However it would have cost Railtrack something like 150 - 200 million. The system will however now be introduced to all trains by 2004.
The facts were taken from BBC online. It is obvious that the main reason for the commercial pressures is cost. The Challenger disaster might have been prevented if sensors had not been removed from the booster rockets. But the cost of some extra sensors compared to the already astronomical cost of space exploration makes it seem a little nonsensical. The cost of a space shuttle is well over $ 1 billion, never mind the damage it did to Nasa's reputation.
However it is not always cost saving that leads to system failures. In both the Denver ALHS and the London Ambulance System CAD it is more a case of money wasting. When the initial investment has been made a company finds it very hard to terminate the project. They would rather get the system working than admit defeat, whatever the cost. Sometimes the cost can be in terms of human lives. This would be why United Airlines still insist on using the Denver ALHS and twenty people died before the LAS switched their dispatching system.
Proper communication and feedback between the designers and the operators will stop a lot of problems like a poor user-interface and incorrect fit between the hardware and software. It all starts with a proper brief being given to the designers. But this can only happen if the management knows what they want. So the only way to have a successful system is to have good communications and understanding between the designers and operators, with the senior managers being kept in the know at all times.
However the most important job is for someone to take responsibility for the design and operation of the system. If someone who is competent is put in charge and takes responsibility then the system is likely to be working properly before its implementation and the operators will have adequate training for using the system. With the London Ambulance System this was doubly important where patients lives are at risk. In situations like these "Ethics" is the key word and there has to be someone held responsible for the actions of the organisation. 4. 0 Bibliography Flynn, Donal J. ; "Information Systems Requirements: Determination and Analysis"; McGraw-Hill Book Company; 1992 Parts; 1985; taken from: Sherer, Susan A. ; "Software Failure Risk Measurement and Management"; Plenum Press; 1992 Jones, Carpers; "Patterns of Software Systems Failure and Success"; Thomson computer press; 1996 Neumann, Peter G. ; "Computer Related Risks"; Addison-Wesley publishing company; 1995 Petroski, Henry; "To Engineer is Human"; MacMillan Publishing; 1985 Flowers, Stephen; "Software failure: management failure"; Chichester: John Wiley and Sons; 1996. Report of the Inquiry into the London Ambulance Service; February 1993.
Simpson, Moira (1994); " 999! : My computers stopped breathing!" ; The Computer Law and Security Report, 10; March April; pp 76 - 81 Dr. Dobbs Journal; January 1997 edition web > web web > web >
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Research essay sample on User Interface Computer Aided
