Systems Life Cycle 100% question and answers

Why should a system be updated? - correct answer Improvements, and conversion to computerized system The job of system analyst: - correct answer Analyse the data processing requirements of the organization Decide whether the current system should be computerized Specify how the new system should work Take the responsibility for implementing the system What are the main stages in the System Lifecycle? - correct answer ADDIDE What are the steps of analysis? - correct answer-Collect data from current system (interviews) -Understand and describe current system -Identify problems -Agree the objectives with the clients -Identify and agree customer requirements -Interpret customer requirements -Produce a cost benefit analysis -Identify suitable hardware and software -Produce a data flow diagram What is cost-benefit analysis? - correct answer Listing both the merits and expenses involved in implementing a particular system Feasibility study broken down - correct answer-Terms of reference -Description of existing system -Criteria -Proposed solution feasibility study - correct answer investigation that gauges the probability of success of a proposed project and provides a rough assessment of the project's feasibility Researching an existing system - correct answer-Observation -Questionnaires -Interviews -Looking at existing paperwork DFD - correct answer data flow diagram What are DFDs used for? - correct answer To describe: -identify inputs, outputs and current system processing -identify problems of current system -identify user and information requirements for new system -new system specification (identify and justify new hardware and new software) Design - correct answer2nd stage after analysis Design key parts of the new system Tasks for Design stage - correct answer Design data capture/input forms Design screen layouts Design outputs in the form of screen displays Produce systems flowcharts Design validation rules Agree on file structures Produce algorithms Design a testing plan Data capture forms - correct answer allow the data to be input into the system drop-down box - correct answer A space saving device that reveals responses when they are needed but otherwise hides them from view. Used when there are limited choices to be made Paper-based data capture forms - correct answer-Clear header -clear answer boxes -use text boxes to limit amount of collected information -use character boxes (each box allows one character only) -Use tick boxes -Clear fonts A computer based data capture form - correct answer-Use on-screen help -Use drop-down boxes when there are limited choices -Use single-click tick boxes -automatic validation of data -Control buttons (save, clear entry) -Double entry verification boxes Reasons for a business to computerize - correct answer Manual system now too slow Increase in business/ More through put/faster through the tills Now insufficient staff/ less staff needed if computerized More accurate stock control Less errors Less space/stationery needed Items which would need to be designed as a part of the file structure: - correct answer Field name Field type Field length Key field Validation check Index Input mask Items that the system analyst will need to design for a database apart from the structure of files - correct answer Data capture forms Input screens/user interface Report layouts Out put screen Validation routines Queries or search routines Some DATABASE features - correct answer To search for information Can sort records Can produce graphs Can save file Can print file/records/data/reports Can produce input forms Easy to edit records Can encrypt data Verification - correct answer Preventing errors when data is copied from one medium from another Methods of verification - correct answer-Double entry: data is entered twice -Visual check: person checking data pro freads Methods of Validation - correct answer Range check Look-up check Length check Character check Range check - correct answer Checks whether data is within acceptable valuable Look-up check - correct answer This checks whether the data entered exists and is stored in a table of data Length check - correct answer Checks if the input data contains the required number of characters Testing strategies - correct answer Normal Extreme Abnormal Changeover methods - correct answer Direct Parallel Pilot Phased Direct method advantages and disadvantages - correct answer-very risky -Benefits are immediate -costs are reduced -less likely of a malfunction Parallel method advantages and disadvantages - correct answer-old system still available as a backup -possible to train employees -more expensive -more time consuming Pilot method advantages and disadvantages - correct answer-Only one branch is affected if system fails -faster and less costly than parallel - correct answer