1. Introducing large ICT systems intoorganisations Part 1Introducing large ICT systems intoorganisations

2. Specification 3. Specification 4. In the next lesson we arelearning how Distributed Systems can be usedOBJECTIVES:OUTCOMES:ALL WILLEVIDENCERead/listen/contribute to the Your teacher has noted yourdiscussion on Distributed Systems contribution, handout notes have beenread.MOST SHOULDAnswer the sample questions EVIDENCEQuestions have been attemptedSOME COULDComplete the homework task during EVIDENCEthe lessonCase Studies have been summarized,text book questions answered. At the end ask yourself: Do I understand theadvantages and disadvantages of DistributedSystems, and therefore why they are used or not? 5. Distributed Systems Large companies usually have their own custom built IT systems(British Airways, NHS, IKEA, DELL, HP) Smaller companies (customers) can be invited to use these systems,to perhaps make orders, track inventory, send data, makebookings/reservations, etc (Travel agents, doctor surgeries, webusers, etc) Advantages for smaller companiesDisadvantages for smaller companiesCheaper system since costs areLittle control over the systemshared Less likely to look for otherGuaranteed to work since thesolutions, especially is a long termlarger company built it, and contract has been signedperhaps other smaller companiesare already using itThere is usually a forum/supportAdvantages for larger companiesgroup of other users of the systemDisadvantages for larger companiesLock customers into contractsIncreased cost of supportControl over the systemIncreased load onservers/networksIf the system goes down, thencustomers will be unhappy, and Introducing large ICT systems into organisationsloss of revenue 6. ExamplesThe hospital has a system for reserving beds, operationscheduling, testing, drug distribution, ordering of supplies,timetables for companies can access this system to conductMany smaller nurses, etcbusiness, make reservations, order drugs, check timetablesetc I can log in to booka bed for a patientof my surgery I can access the system I can log in to see if to request a test to beI can log in to see whatthe hospital has conducted on a blood drugs the hospital needs,room for myIntroducing large ICT systems into I can send them (andsample soemergency patientorganisationsinvoice them) 7. ExamplesNewsagents will use the NewYork Times Distributed Systemto:Change the number ofnewspapers they want to order inthe coming daysEnter the number of newspapersthey have not sold (they do notpay for these)Look up how much money theyowe the NYTCheck delivery schedulesArrange for non soldnewspapers to ICT systems intoIntroducing large be collectedManage subscriptionsorganisations 8. Sample Questions 1. You are starting up a new computer shop. You have achoice of suppliers for the hardware you will sell. Only oneuses a Distributed System that they will provide for your use. A) What advantages for your shop does this Distributed Systemoffer? (4 marks) B) If you use this system, what are some disadvantages? (4marks) List some of the things you would expect you could do with suchAnswer A:a distributed system. (4 marks)Cheaper to set up than creating your own system (1), so the computer shop canspend cash elsewhere (1)The system would have been tried and tested by other computer shops (1), so fromday one of use the new computer shop will know it works (1)Answer B:The supplier can control the system (1), so if there are issues, you will depend on thesupplier to fix them (1)The system is cheap and easy to get started, so the new computer company is lesslikely to bother to hunt out better/cheaper/faster suppliers (1), which means the newcomputer company may not be getting the best deals/hardware/service (1)Answer C:Order hardware, review past orders, check prices, look up invoicing, make payments,apply to return faulty goods, track orders, lookup technical specifications of hardware,Introducing large ICT systems intogain access to the latest hardware, download updates/patches (max 4 marks)organisations 9. Homework Read AQA ICT for A2 Level pages 147 150 (top) 1. There are 3 case studies. Summarise the first two,including: Name of organisation/s What the distributed systems does Answer all questions on each case study.Introducing large ICT systems intoorganisations 10. Name of organisation Smiths News PLC What the distributed systems does Allows Smiths to deliver 60 million newspapers and magazines a week tocustomers. The system allows for the tracking of newspapers/magazines from thepublishers to the warehouse and then to the retailers. It also assists in the repackaging of stock for distribution to retailers Allows wholesalers, publishers, and retailers to log in and use trackingand/or ordering systems (run by NewsWorks a part of Smiths) Generally the system allows for a more efficient method oftracking/ordering publications Answer all questions on each case study.Why is it an advantage for a newspaper publisher to use NewsWorks order processing and tracking system rather than to develop one of their own?There are a few reasons: The system is already set up (1) and so probably has been tried andtested for a long time (1) It will be a lot cheaper (even free!) to use the system that is provided(1), rather than build a bespoke system (1) Introducing large ICT systems into There should already be Support Desk/Forum/Online help on theorganisations 11. Name of organisation The NHS What the distributed systems does Allows authorised medical personnel to access patient clinical data andgeneral statistical information Patients can use the Choose and Book system to select the place andtime of their next appointment An electronic prescription system allows drugs to be sent from prescribingdoctor to pharmacy of choice so patient can easily collect it Answer all questions on each case study.1. Some people feel that the new systems could cause a threat to patient privacy. Can you justify their concerns?oThe system is accessed all of the country. It depends on staff keeping their personal login and password details secure (1), so all it takes is for one authorised user to leave their details lying around for someone to see, or to not log off/lock computer when not using it (1)oThe personal health data of patients in stored in electronic format, so it can be copied, backup media lost, intercepted in transit from server to pc, or even maliciously deleted/tampered with. (1)o(Imagine if health insurance companies got hold of the data!)Introducing large ICT statistics used in the system, is all identification of individualsoIn the systems intoorganisationsremoved? (1) 12. Answer all questions on each case study. o Discuss the advantages of the Choose and Book system to the patient. Hospitals/clinics closer to home can be selected (1). Therefore thepatient does not have to travel so far (1), which can save them time,money, distress, effort (1) A convenient time can be selected (1), which fits into the schedule ofthe patient (1) o What are the benefits of the electronic prescription system to: The GP Surgery Electronic orders = less paperwork (1), so more time can be spenttreating patients (1) Orders are transmitted instantly (1), so patients are treated quicker(1) which reduces the number of return visits, and increasesreputation of surgery (1)The pharmacy Orders are delivered electronically (1), so there is less paperworkand more time can be spent dispensing prescriptions (1) Higher likelihood of repeat orders since the their business isavailable in the NHS system (1), which increases profits (1)The patient Can elect a pharmacy where the prescription will be collected (1)Introducing large ICT systems into convenient (1)so it is moreorganisations 13. In the next lesson we are:researching the NHS and the features of the Large Scale System it introducedOBJECTIVES:OUTCOMES:ALL WILLEVIDENCESelect one of 2 topics to researchA topic has been selectedMOST SHOULD EVIDENCEUse the Internet to research the stated At least 3 Internet sources have beentopic, and collect information on itidentified, and the information(bullet pointed)contained summarisedSOME COULDEVIDENCEConvert the bullet pointed notes into Essay has been written and submittedan essay worth 10 marks At the end ask yourself: Could I produce 5 paragraphs of work on my chosen topic? 14. SystemsSince 2005 the NHS in the UK began working to introduce a Large ScaleSystem to maintain all health data on patients, and make it available to thosethat need it. There are valid reasons for attempting such a large scale project,however it has not been as successful as it could have been. Select one ofWhytopics below, and performLarge research on it.the the NHS needed a new some Problems the NHS has faced in Scale System attempting to introduce a new Large Scale SystemFor each reason:For each problem identified:Original Problem Original ProblemHow new NHS system would improve How new system tried to solve itthisProblems facedWho benefits from this improvement?CriticismsURL where you found this information URL where you found this informationDate of articleDate of articleYour opinion Your opinion(start at www.connectingfor (start at http://www.computerweekly.com)health.nhs.uk)This is an excellent exam question/essay worth 20 marks. Plenty of opportunities to earnmarks for stating :Reasons why a Large Scale System would be introduced (5 marks)Examples (from NHSNHS) (5 marks)Problems faced when introducing a Large Scale System (5 marks)Examples (from NHS) (5 marks)Introducing large ICT systems intoorganisations 15. Links to articles about NHS IT Article 1 Information System Failures and the NHS http://goo.gl/8bILr Article 2 - Six reasons why the NHS National Programme for IT failed http://goo.gl/y4jZB Article 3 - Three reasons why NHS privacy and data-handling should be an election issuehttp://goo.gl/A3Jxh Article 4 Wikipedia article on NHS Connecting for Health http://goo.gl/H8WvQ Links to articles about General IT projects in UK Article 1 UK wasting billions on IT projects http://goo.gl/MLdC1Introducing large ICT systems intoorganisations 16. When testing is incomplete, a realdisaster can occur!Introducing large ICT systems intoorganisations 17. Introducing large ICT systems intoorganisations 18. Sometimes implementations of Large ScaleSystems are not successful. This can be for many reasons. design of these are:Poor analysis Poor Some Incomplete testing Lack of trainingLack of staff Incompatible componentsHardware changes before the project is completed Links to articles on software failures 20-famous-software-disasters - http://goo.gl/ZSEMm Top-10-it-disasters-of-all-time - http://goo.gl/0QIb2Introducing large ICT systems intoorganisations 19. System What was it supposed to Cause of the problem Cost?do? What went wrong? UKBring the Passport Agency1. Staff not trained Millions ofPassportinto the modern age,2. Lack of testingPounds system speed up issue of3. New law introduced that Reputation1999passportsincreased demand for BUT passports AirbusAssist in the building of theA380 new Airbus A380 plan DesignBUTSoftware issues2006 MarsTravel to Mars and land onClimate the planetObserver BUT 1998 Introducing large ICT systems into organisations 20. In the next lesson we are: learning about the types of testing required for largescale systemsOBJECTIVES:OUTCOMES:ALL WILLEVIDENCERead the notes on Testing Notes are readMOST SHOULD EVIDENCECreate bullet point summary notes A word document of notes has beengeneratedSOME COULDCreate a Power Point Flow Chart EVIDENCEsummarising the testing of large scaleDocument is created and printedsystems At the end ask yourself: Could I produce 5 paragraphs of work on my chosen topic? 21. Reliability and TestingWhenever a new system is developed extensive testing must be planned andcarried out. Often teams of people are involved. This can be the mostexpensive phase in the development of software!This chapter is about Large Scale Systems, however do not forget the followingfor all systems: TYPE OF TESTING Module testingBoth small Functional Testing (or Black Boxsystems and testing)Large Scale System Testing (or Alpha testing)Systems need User Testing (or Beta testing) these tests Operational TestingHowever in Large Scale Systems more attention needs to be paid to certain testtypes, and there are even a few extra tests to perform! These are mostly to dowith :Testing the system works on a networkTesting the network still works with the system on itTesting the system works with many users at onceThere are companies who will actually test software for developers. This can work out cheaper than doing it in house. Utest is a company that tests Mobile Phone Apps for developers. Click HERE for more info.Introducing large ICT systems intoorganisations 22. Reliability and Testing task From Nelson Thomas AQA A2 text book : Read pages 72-75 on 7.2 Reliability and Testing Create summary (bullet pointed) notes on: To ensure large scales systems always operate as expected, the following 4 categories of tests are completed: Functional tests: Performance tests: Usability tests: Security tests: Designing testing to ensure reliable operation Requirements based testing Program testing System testing Regression testing Change control Alpha testing Beta testing Testing network based systemsIntroducing large ICT systems intoorganisations 23. Reliability and Testing taskFrom Hodder AQA A2 text book :Read pages 150 - 153 on Reliability and TestingCreate summary (bullet pointed) notes on: Developer testing Code walkthrough Functional testing Automated testing Surviving unusual events Compatibility testing User Acceptance Testing Testing network systemsIntroducing large ICT systems intoorganisations 24. Testing Systems Functional Testing System Testing Module Testing (aka Black Box(aka Alphatesting)testing)User TestingOperational (aka User testing)TestingIntroducing large ICT systems intoorganisations 25. In the next lesson we are: learning about the types of testing required for largescale systemsOBJECTIVES:OUTCOMES:ALL WILL EVIDENCEIdentify reasons for why a large ICT I can state at least 5 reasons why aSystem development might faildevelopment might failIdentify 4 areas that should be looked I can state the 4 areasat when testing to ensure the systemoperates as expectedResearch and understand the differentA concise definition of each type oftypes of testing carried out on largetesting is presented and rememberedscale ICT systemsby all (testing required) 26. Why might a large ICT System fail? Poor analysis of the initial problem Poor design of the intended solution Lack of training offered before implementation Lack of support provided during the implementation stage Lack of staff Incomplete components Hardware changes before the project is completed Poor testing (e.g. incomplete testing, getting the wrong people to test it)Introducing large ICT systems intoorganisations 27. List at least three corporate consequences of system failure Any business that loses its computer data will facefinancial loss If the computer system is not working, they will notbe able to process transactions which are at theheart of the business (loss of trade) Repeated failure is likely to lead to a company beingforced to stop trading Customers may lose confidence May lead to a poor reputation 28. Testing of Large Scale SystemsIntroducing large ICT systems intoorganisations 29. Testing This chapter is about Large Scale Systems, however do not forget the following for all systems:TYPE OF TESTINGModule testing Both smallIntegration systems andFunctional Testing (or Black BoxLarge Scaletesting)Systems needSystem Testing (or Alpha testing)these testsUser Testing (or Beta testing)Operational Testing Introducing large ICT systems into organisations 30. Task 1 You have 15 minutes In groups you must: Create 1 slide per test type (there are 6 types) On that 1 slide you must Put a title which should be the name of the type of test Write a short definition of that type of test Deligate in your groups however you like BUT you must ALL know the definitions of each (you will be tested)Introducing large ICT systems intoorganisations 31. Task 1 The testing types are: Module Testing Integration Testing Functional Testing Systems Testing User Testing Operational TestingIntroducing large ICT systems intoorganisations 32. Tell me about Module Testing Also known as unit or component testing Involves testing each individual section of thesoftware Written from a programmers perspective An example of white box testing 33. Tell me about integration Testing Where modules are combined one at a time and debugged 34. Tell me about functional Testing Tests the operation of the system Written from a users perspective Example of Black Box testing (does a given input produce the correct output?) 35. Tell me about System Testing Tests the complete integrated solution Tests that transactions are processed correctly from beginning to end 36. Tell me about User Testing Where actual users test the system User documentation must also be tested at this stage 37. Tell me about Operational Testing Conducted in the environment in which the solution will be working or a simulated version 38. Testing large ICT Systems is a complex task what 4 areas will be looked atwhen testing to ensure the system operates as expected? Functional defects errors in the system that effectthe accuracy of the output Performance defects - errors in the system thateffect the speed of input, process and output Usability defects Errors in the aesthetics/structure/layout/navigation of the system whichmeans the user cant used it effectively Security defects errors in the system which meansusers can intentionally/accidently gain access torestricted areas/data 39. Task 2 You have 25 minutes In groups you must: Create 1 slide per test type (there are 9 types) On that 1 slide you must Put a title which should be the name of the type of test Write a short definition of that type of test Deligate in your groups however you like BUT you must ALL know the definitions of each (you will be tested)Introducing large ICT systems intoorganisations 40. 9 Types of Testing Client requirements based testing Program testing (similar to code walkthrough) System testing Regression testing Change Control Alpha Testing Beta Testing White Box Testing Black Box Testing 41. What testing techniques can be used when testing large ICTsystems and what people are involved in each technique? Client requirements based testing Testing team should be involved in writing the requirements to ensure that each can be tested Program testing (similar to code walkthrough) In development teams the code is read through against a checklist of common problems (Debugging programs could alsobe used) System testing Following the test plan and using normal, erroneous and extreme data to test the whole system processes the input andprovides the correct output Regression testing Re-running earlier tests once changes have been made (making sure the change in code hasnt had a knock on effectand broke something else) Change Control Making sure that any changes happen in a controlled and coordinated way and well documented (must assess theimpact on all parts of the system) Alpha Testing Carried out by the software house, based on the test plan (users may have input). Results may require modifications untilthe system is reliable enough to be tested by a wider audience Beta Testing Software being tested by a selected group of real users who use the system under normal conditions. Will report backwith any problems, which will then be resolved before final release Whit Box Testing Testing of the program by people familiar with programming (programmers). Checks the program code is written correctly Black Box Testing A technique used by people who never look at the programming code. They look at the output produced and check if the 42. Tell me about Client requirements based testing Client requirements based testing Testing the system against the client requirements A type of Black Box testing Testing team should be involved in writing the requirements to ensure that each can be tested 43. Tell me about Program Testing Where the code of the program is read through andtested A type of White Box testing Often done in teams Also referred to as a Walkthrough 44. Tell me about System Testing Tests the system against the specification Uses normal, erroneous and extreme data to test the whole system processes the input and provides the correct output 45. Tell me about Regression Testing Re-running earlier tests once changes have been made, making sure the change in code hasnt had a knock on effect and broke something else. 46. Tell me about Change Control Making sure that any changes happen in a controlled and coordinated way and well documented (must assess the impact on all parts of the system) 47. Tell me about Alpha Testing Carried out by the software house It is based on the test plan (users may have input). Results may require modifications until the system is reliable enough to be tested by a wider audience 48. Tell me about Beta Testing Software being tested by a selected group of realusers who use the system under normal conditions. Will report back with any problems, which will thenbe resolved before final release 49. Tell me about White Box Testing Testing of the program by people familiar withprogramming (programmers). Checks the program code is written correctly 50. Tell me about Black Box Testing A technique used by people who never look at theprogramming code. They look at the output produced and check if therequirements are met 51. Testing network based systems (which most large scalesystems are) is vital. You must test: The effect of the new system on the running of thenetwork The effect of the network structure on running thenew system If testing a WAN it might be better to simulate this so as not to cause disruption within the company Testing a network based system requires specialist skills and facilities 52. Installation of Large Scale SystemsIntroducing large ICT systems intoorganisations 53. There are 4 different methods for installing a newsystem into a workplace, what are they? Direct Changeover Phased Changeover Pilot Running Parallel Running 54. 10.12 Explain the concept of a Direct Changeover and identify the advantages and disadvantages of this method Direct Changeover Old system stops, new system startsAdvantages of Direct ChangeoverDisadvantages of Direct ChangeoverThe quickest of all the methods (As longDifficult to train staff as the new system isas it works) not available beforehandLess risk of staff being confused between Stressful for users if not trainedthe old system and the new one Stressful for system developers (small window to implement this changeover, transfer data etc.) Very risky method, if new system doesnt work, nothing to fall back on 55. 10.13 Explain the concept of a Phased Changeover andidentify the advantages and disadvantages of thismethod Phased Changeover New system is brought in stages, each stage replacing part of the old system e.g. of a new school management system introduce just the attendance par of the system, then maybe the reports, then monitoring etc.Advantages of Phased ChangeoverDisadvantages of Phased ChangeoverVery structured, allows for each phase to Slower than direct changeoverbe fully evaluated before introducing theComplete system can not be evaluatednext one until all phases are implementedLess risky than direct changeover Integrating each phase of the new systemStaff can be trained as each phased iswith the old can be complexintroduced rather than everything all atonce 56. 10.14 Explain the concept of a Pilot Running andidentify the advantages and disadvantages of thismethod Pilot Running New system replacing the old one but only on a small scale e.g. a single branch might use it, or a particular department before being introduced and used by everyoneAdvantages of Pilot Running Disadvantages of Pilot RunningMuch easier to control as a pilot can be Slow to roll outhalted at any timePilot may not show problems that exist inEasy to monitor and evaluate (canfull scalecompare to old system still running)Organisation will be running two systemsEasy to train staff by using pilot systemat one timeas a training systemLow risk if fails 57. 10.15 Explain the concept of a Parallel Running andidentify the advantages and disadvantages of thismethod Parallel Running Old system and new system running alongside each other but working independentlyAdvantages of Parallel Running Disadvantages of Parallel RunningEasy to compare to old system (is the Very expensive method (duplication ofnew system out performing?)staff and hardware)Lowest risk as old system can still beStaff may get confused by having toused if new system fails remember two sets of different proceduresStaff can be trained gradually 58. Were developing a large system, we know documentation isrequired. What documentation is required and who requires it? System documentation For the programmers who will maintain the system User Documentation For the users so they can operate the system When any new system is installed new users willneed to be trained! Change Logs Used to document the changes in versions E.g. Twitter and Facebook use them for their APIdevelopment to document when changes were madeand the versions 59. When handling the installation of a new system it is veryimportant to consider the resources you have availableto you, why? Existing infrastructures might support or negativelyeffect the installation Existing hardware might be of use or need replacing Existing software might support the planning processor hinder the compatibility Financial issues might restrict installation choices ortraining The people you have available might have thetechnical expertise to carry out the installationthemselves 60. Backup and Recovery involved with implementing large scale systemsIntroducing large ICT systems intoorganisations 61. What are the potential threats to data in alarge scale system Inappropriate usage of devices Network data breaches Laptop Loss/Theft Lack of Education Natural disasters Sabotage/Terrorism 62. What is the purpose of producing filebackups? To make sure that if data from a computer system is lost or corrupted for any reason, the files can be recovered and the computer system restored. 63. What strategy do companies put inplace to avoid data loss? A disaster recovery strategy / backup and recovery strategy 64. What factors should be considered whendevising a disaster recovery strategy ? The best time to backup How often to back up The type of backup to use Whose responsibility it is to backup The media that will be used Where the backup media will be kept A log of backups taken Testing the recovery of backed up data 65. What is the first stage in setting up adisaster recovery strategy? Risk Analysis 66. What is the purpose of risk analysis andwhat does it involve? Used to identify the main elements of the informationsystem A value to the business of each element is assigned Any threats to that element are then identified The likelihood (probability) of such threats occurring arethen established The speed with which that piece of data needs to berecovered The severity of each element is then clearly established 67. What are the contents of a disasterrecovery plan? Alternative computer hardware If hardware is damaged what alternative is in place? Backup procedures What type of backup method and media will be used? Recovery Procedures What is the plan/order for restoring data? Staff responsibilities Who is responsible for doing what? Alternative working location If the building is damaged what is the solution? 68. Full, differential and incremental backups are methods which canbe used to backup data, explain each of these Full backup All data stored is saved Differential backup Saves only data that is different from the last full backup issaved Incremental backup Saves all of the files that have changed since the last backup whether that be full, differential or incremental 69. There are alternative backup options availablefor large scale systems. Your homework is to find out about these 6 alternative methods: Failover systems Replicated systems Regular snapshots Periodic backup Tape Backup Archiving 70. There are alternative backup options availablefor large scale systems: Failover systems If a server fails it is setup to automatically switch over to an alternative server The server will pickup the service from the point at which it failed Users a heartbeat cable (If the heartbeat dies the changeover occurs) Vital for e-commerce Replicated systems Used on databases As data changes in the database a replica is automatically created in case of failure Provides quick recovery Regular snapshots Frozen image of a file system at a given instant of time Backup several times a day Does not require large amounts of storage Short backup windows Periodic backup Backup to a separate hard disk at intervals Can be full, incremental, differential 71. There are alternative backup options availablefor large scale systems: Tape Backup Still regularly used Uses data tape drives and disks to backup Tapes can be taken off site Archiving Useful for backing up data The data that is achieved may not be neededimmediately Data that has not changed for a long time is stillaccessible 72. Procedures for recovery of large scale systems is essential, they provideguidance and actions for restoring the system. What procedures / stepsshould be followed when restoring a large scale system? Step 1 Estimate the situation Evaluate the extent of the problem, the likely case of failure and the amount of data lost Identify the state of the backup copies Step 2 Evaluate available resources Human and hardware Make sure expertise is available Make sure there is sufficient hardware Step 3 Set up Install good hard disks into functioning hardware, check power supplies and cabling Step 4 Recovery run Install data recovery software and run it Step 5 Evaluate the results Undertake a manual review of most important files Step 6 Clean up Remove any corrupt files 73. For each element of data in an information system that needs to berecovered an RTO is established, what is this? RTO stands for Recovery Time Objective. It defines the maximum time allowed to reloadrecovered data and get the system fullyoperational again. 74. For each element of data in an information system a DataRecovery Point needs to be established, what is this? A Data Recovery Point is the last point at whichdata can be recovered i.e. the time lapsedbetween backups E.g. If the data is backed up overnight, the DataRecovery Point is last night and there is thepotential to lose 24 hours worth of data. Reducing the RTO is expensive so it is importantto balance the importance of the data againstpotential cost 75. Rearrange this diagram to show appropriate backup methods andRTOs (Recovery Time Objectives)CoNeed Protecting(Records) Periodic back up to disks Rt e Failover systems that pick up cNear Critical O ooperation instantly and(Databases) f vautomatically eP r Important Archive r y (File systems) Back up to tape o Tt i Replicated systems for quicke Mission Critical mrecoveryc(E-Commerce, Email) e Regular data snapshotstion 76. Rearrange this diagram to show appropriate backup methods andRTOs (Recovery Time Objectives)Co Failover systems that pick up s Mission Critical(E-Commerce, Email)operation instantly and t R eautomatically c Replicated systems for quickONear Critical o(Databases)recoveryf v Regular data snapshots e ImportantP r (File systems) Periodic back up to diskr yoNeed Protecting Archive t T(Records) Back up to tape e i mc etion 77. There are 5 possible accommodation solutionsfor large scale disasters i.e. fires, what arethese solutions? Use existing accommodation (if equipment is destroyed but thebuilding isnt, replace the equipment) Alternative accommodation (If the disaster has destroyed the buildingand the system, alternative accommodation is required) Reciprocal site (Arrangements may have been made with a similarorganisation that have a similar system) Standby site (Is dealing with sensitive data a company might have acomplete and up-to-date second system installed at a differentlocation *See next slide) Contract with specialist disaster recovery company (Provideaccommodation and equipment if and when necessary, still can beexpensive)The appropriate option should beconsidered and included in the disaster 78. There are two types of standby sites,what are they? Cold Standby site Duplicate system Tested on a regular basis Not used unless there is a disaster Hot Standby site The duplicate system is up and running as a mirrorsite Processes the same live data as the main site(s) atthe same time 79. Maintenance of large scale systemsIntroducing large ICT systems intoorganisations 80. It is important to carry out maintenance once a systemhas been installed. What 3 types of maintenance arethere? Corrective maintenance Putting right any reported errors once the system isoperational Adaptive maintenance Altering the system to meet new organisation,legislation or security requirements Perfective maintenance Where any inefficiencies are tweaked i.e. make thesystem even better 81. Name two types of models that can be followedwhen providing maintenance Quick fix Identify the problem and fix it as quick as possible No consideration to the long term effect Not ideal for large scale systems Iterative enhancement Has 3 stages System is analysed Proposed modifications classified Changes implemented 82. Past PaperQuestions 83. Past Paper Questions 84. Past Paper Questions 85. Past Paper Questions