Revision Notes - Topic 1 PDF

Topic 1 Revision Notes  New systems and change management Identify three context in which new system might be needed 1 If hardware outgrows software new software may be needed to make applications compatible with the new hardware. 2 As other competing software is develop...

Topic 1 Revision Notes  New systems and change management Identify three context in which new system might be needed 1 If hardware outgrows software new software may be needed to make applications compatible with the new hardware. 2 As other competing software is developed many businesses will have higher expectations for the software and may change to different software if they are not met. 3 If there are software bugs or security issues a new software must be developed to fix those issues and keep the user's/ business' information safe. 4 Government legislations and User roles in the organisations are largely changed and current system is not compatible with the processes of the organisations List the factors that can lead to a successful change and can lead to issues if not addressed ( change management) Factors to be considered in the change management Successful Change management 1 Training of the staff ( identify any redundancy) 1 Employee training on a software can be vital to how successful the change is 2 Duration of testing of the new application 2 Everybody must be happy with the changes 3 Decision about changeover ( parallel, phased, …) made and changes should be made to benefit 4 Time frames of data migration and planning to everyone implement new system 3 The software must meet what is desired by 5 Decision about cost ( hardware/ software/ training..) the user/ business 4 Time frame and budget planned is met in the transition process Issues of Legacy Systems and their maintenance and migration Data Migration issues ( Incompatibly and Data loss) Data loss Incompatible formats Language differences/different character set used in two systems; Different conventions of representing various data/currencies, dates, etc; Different data validation criteria used in two systems Incompatible software/incompatible hardware; SAAS: characteristics and advantages and disadvantages The characteristics of the SAAS( Software as a Service) applications. You must mention three points to get the full mark, hosted remote, accessible through internet connection and are paid ( subscription) Features Benefits 1 It is a contemporary delivery method that enables both software or data to be hosted on a remote datacenter that is Cheaper than developing and hosting your own software not owned by the company Less staff is needed as less IT members will be needed because 2 They are usually provided through a subscription meaning the the business is not directly managing the software business has to pay either monthly or yearly to access the software A business can change it's SAAS subscription based on the needs of the business 3 They are based on the cloud and require a web browser and an internet broadband connection to be accessed Disadvanta ges They shouldn't be used to store private/ valuable information as the business hosting can access it at anytime They are not as worthwhile in the long term as at some point it becomes more expensive to pay for access instead of just hosting your own software The performance could differ depending on the internet connection speeds as well as the performance of the web browser/ application that it is run on The remote host in different time zone, this may have impact to offer service to the clients in another region  Direct Changeover Phased Conversion Implementati is the cheapest and quickest/the old method where the old system is still in use but parts of the new system or on/ system is completely switched by the new one; modules are introduced, involves bringing in the new system one step at a Installation this is straight forward but also the riskiest / no system available to fall back on; time; less risky than direct changeover; less methods: no need to keep data duplicates; risky if new systems has any issues, it will only affect the specific part; Phased and it allows the organization to change the system when most convenient; takes long time of transition from old to new system; direct change the employees have very little time in order get use to the new system as employees have sufficient time for training/to get use to the new system / are introduced to the changes in small over the change is instantaneous; there is a period ( short) when neither stages; Employees/users could ask for systems are operational; changes which then hold up the installation of the next phase which helps improving the system; Implementation/ Installation methods: Phased and pilot change over Parallel implementation Pilot change over Old and new system runs at the same time for some duration New system will be installed in one of the before moving on to the new system Output results can be compared with known results , branch of the organization/ company. After sufficient opportunities and time for comparison and testing testing , evaluation and improvements, will of new system be rolled out In the case of any difficulties system operation continues under the old system It is time consuming and long process. Slow and inefficient method of implementation; Less risky than other methods of Duplication of work and resources to keep both systems updated implementation. Parallel running ensures new system runs without errors; if Teams trained to use the system in pilot errors are found, refer to old system to resolve and make modifications to new system can train others. Parallel running allows staff can be trained in the new system Impact of any failure of the system is gradually; helps them gain confidence in new system limited to only pilot branch. DON’T MENTION MORE ENERGY/POWER SUPPLY REQUIRED How to compare two implementation methods List advantage / disadvantage of one and compare with other 1.Parallel running is less risky than direct changeover, if the new system fails, operation can continue under the old system; whilst in direct changeover if the new system fails the data is lost/ operation cannot continue. 2.Parallel running allows organization to test the new system (all features of the new system can be fully trialed); and the organization switches over to the new one if(when) it is found to be more efficient than the old one; Whilst in direct changeover the new system is started without ensuring that the new system is working correctly/efficiently before the old system is terminated;  Type Done by Reason of testing Alpha testing Developers Alpha Testing is a type of acceptance testing; performed to identify all possible issues and bugs before releasing the final product to the end users. Alpha testing is carried out by the testers who are internal employees of the organization. The main goal is to identify the tasks that a typical user might perform and test them. To put it as simple as possible, this kind of testing is called alpha only because it is done early on, near the end of the development of the software, Testing and before beta testing. The main focus of alpha testing is to simulate real users by using a black box and white box testing techniques types and Beta Testing End users for short Beta Testing is performed by "real users" of the software application in "real environment" and it can issues duration of time be considered as a form of external User Acceptance Testing. It is the final test before shipping a product to the customers. Direct feedback from customers is a major advantage of Beta Testing. This testing helps to test products in customer's environment. Beta version of the software is released to a limited number of end-users of the product to obtain feedback on the product quality. Beta testing reduces product failure risks and provides increased quality of the product through customer validation. Debugging Developers/ This is the process of finding and correcting any ( white and Debugging remaining bugs within the program. Done during the  BL ACK-BOX TESTING As the programmer, you can see your program code and your testing will involve knowledge of the code (see white-box testing). As part of thorough testing, a program should also be tested by other people, who do not see the program code and don’t know how the solution was coded. Such program testers will look at the program specification to see what the program is meant to do, devise test data and work out expected results. Test data usually consists of normal data values, extreme/boundary data values and erroneous/abnormal data values. The tester then runs the program with the test data and records their results. This method of testing is called black-box testing because the tester can’t see inside the program code: the program is a ‘black box’. Where the actual results don’t match the expected results, a problem exists. The programmer needs to find the reason for this discrepancy before correcting the program Once black-box testing has established that there is an error, debugging software or dry-running have to be used to find the lines of code that need correcting.  WHITE-BOX TESTING Suitable test data that checks every path through the code. This is called white-box testing. A good way of checking that an algorithm works as intended is to known as a walk through. dry-run the algorithm using a trace table and different test data. The idea is to write down the current contents of all variables and conditional values at each step of the algorithm. A L P H A , A C C E P TA N C E A N D B E TA TESTING Soft ware will be tested in-house by software testers before being released to customers. This type of testing is called alpha testing. Bespoke software (written for a specific customer) will then be released to the customer. The customer will check that it meets their requirements and works as expected. This stage is referred to as acceptance testing. It is generally part of the hand-over process. On successful acceptance testing, the customer will sign off the soft ware. When software is not bespoke but produced for general sale, there is no specific customer to perform acceptance testing and sign off the soft ware. So, after alpha testing, a version is released to a limited audience of potential users, known as ‘beta testers’. These beta testers will use the soft ware and test it in their own environments. This early release version is called a beta version and the chosen users perform beta testing. During beta testing, the users will feed back to the soft warehouse any problems they have found, so that the soft warehouse can correct any reported faults.  Can lead to software which is not appropriate for the purpose it wasintended/can lead to the system not meeting user requirements; Can lead to (undiscovered) bugs in Consequen software/errors in the system; ces of Can lead to end user dissatisfaction; inadequate testing Can lead to reduced (employee) productivity; Can lead to decreased reliability of the organization; Types of documentation and Training Self-instructions ( training ) Users learn on their own (materials are Internal/ Technical documentation provided). May include reading a manual or watching a tutorial. includes Code block with comments Lowest cost - only materials are required, Useful and meaningful module class and no instructors and classrooms Flexible timeline Training tailored to the user variable names Users might feel overwhelmed due to lack Indented and readable code of guidance / support Code structure and the data structure Unstructured, so some functions might be ignored by the user used ( data dictionaries and validations) Self-discipline and motivation required from External/ User documentation is the student written externally for the user e.g. a user Formal face to face trainings Users sit in a traditional classroom with other students and a teacher. guide, User FAQ,Advantages Steps to use the new system Disadvantages Structured learning environment The teacher can answer any questions that Documentatio n arise Designed to teach all aspects, including the Printed Very thorough guide on Difficult and expensive to ones that may be difficult to understand Manuals how to do most if not all produce and distribute Expensive - teachers, facilities, buildings (Physical) things on the new Updates and edits are difficult needed. system / long process Tight schedule and curriculum Always available / no Can be damaged and lost Not much personalization possible need of internet/ device In big classes, not much time to deal with individual problems/questions Online Help Cheap and easy to set Require internet connection/ files/ up device to access it. Remote online trainings Instructor trains users individually or in small documentation Can be updated / groups via remote connection Revised Most effective as it can be suited to Easy to search individual needs Accessibility ( read out An expert teacher that guides you through loud, contrast colors the learning ( Visually impaired, Flexible schedule dyslexia) Expensive - teacher and internet connection required  Social and Different context are provided in the exam Ethical issues question, always discuss these points and may arise with make sure to relate to the context of the question new system Social 1 With new IT system , work expectations may change. Staff may have to upgrade their digital skills. Social 2 Some computerization means automation of processes that may lead to loss of jobs/ redundancy - like if an electronic home assistant makes phone calls to make appointments that means the call center staff may lose jobs. These issues must be considered that how this staff can be upskilled to use for management of the new systems. Ethical Data Security - What kind of data will be gathered, where will it be stored and what are they going 1 to do with the data and how long is it going to be stored , are the owners of the data aware of this process , have they provided consent for this. Ethical How addicting is it - Will people prioritise the program over their connection to the real physical 2 world. Too much of dependence may lead to addictions/ health issues/ work ethics Social/ Ergonomic standards (human-computer components) are considered, and accessibility and Ethical accommodation is provided for everyone with different needs Reasons of Data Loss and how it can be avoided, or impact can be reduced  1.1.12 - consequences of data loss in a specified situation Consequences of data loss: Loss of medical records – patient's life could be in danger if medical records are lost. Cancellation of a hotel reservation without the knowledge of the traveler – the traveler might arrive to the place and have no place to stay, or they might even not be let in the country if their booking is cancelled Can impact reputation and productivity of the businesses Consequen 1.1.13 - Range of methods that can be used to prevent data loss Failover system ces and A failover system is a standby/redundant system; Which is used to eliminate/reduce the impact on users/owners; prevention By automatically taking over if the primary system suddenly becomes unavailable; Redundancy - data is stored twice, either in the same database/software or in separate ones Removable media - storage devices that can be removed from a computer (flash drives, CDs, DVDs etc.) Offsite storage - stored in a facility / storage media not physically located on the organization's premises Online storage - cloud storage. Files stored in a remote server that can be accessed through internet. Uninterrupted Power supply – To safe the data and for the safe shutdown of system in case of power failure  Update - usually free. Contain fixes for the program or new functions, but usually quite minor. Patches - all patches are updates but not all updates are patches. Patches contain fixes for bugs, updates contain new features/functions. Improves security of the system Upgrade - mostly paid. Unlocks new functions. Can be a subscription for a 'pro version' or a once-for-life upgrade. System How to get updates / patches Manual - you have full control, but it is time consuming, user has to Deployme check the availability of the patches and download and install it by their selves. nt Automatic - don't have to worry about it but lack control. This helps to automatically check when the updates are available download them and install them. ( Updates / How system knows that update is releases When the software is installed and registered (a cookie is placed on Patches) the machine); This communicates with the software developer automatically on startup; Messages about updates are sent back to the machine and alerts are given; Why patches and updates are installed To provide improved functionality/new functions/usability/maximise efficiencies; To generate income for the software company/to innovate and stay ahead of other software companies; To ensure compatibility with other (updated) technologies; Role a Computer system can take Hardware The physical elements of a computer. E.g., Screen, CPU etc. Software A term that describes computer programs applications or sets of instructions. Human Refers to the people who are/could be used by an organization. Also refers to the department Resource responsible for managing employee resources. Peripheral An external device that provides input, output or storage for the computer. E.g. Mouse, Monitor, Keyboard, Hard-drive etc. Peripheral are directly connected to the device Client in a The client in a network receives data/ service via the network. Client request for services from network the server in the network or other devices in the network Server in a A computer that provides data/ services/ resources to other computers network Types of server are web servers, file servers, mail servers Each runs software specific to its purpose Email A type of server that manages the flow of e-mails in and out of the network. It can also check if server an email address is valid, allow users to access the email etc. DNS server Translate domain name to network/IP addresses. This allows the users of networks to utilize user-friendly names when looking for other hosts instead of remembering the IP address. If a client / a web browser sends a request containing a hostname, then a piece of software such as DNS resolver sends a request to the DNS server to obtain the IP address of a hostname. If DNS server does not contain the IP address associated with a hostname, then it forwards the request to another DNS server. If IP address has arrived at the resolver, which in turn completes the request over the internet protocol Firewall A hardware / software-based application that filters and inspect the traffic flowing in and out of the network. When the data packets meets the specific requirement then they are allowed in and out otherwise they are blocked. Router A networking device that accepts data packets, reads their address and routes the traffic to the outer network and also routes the packet in the network from outer network File server A central server in a network that stores data in files and folders in a shared space for the clients Relevant stakeholders of a new system and their roles in the process of planning Stakeholder - a person, group or organization that has interest or might be affected by a project Can also be a user of current system (can identify flaws and potential improvements) Internal: directors, managers, employees, owners (shareholders) External: creditors, government and its agencies, suppliers, unions, and the community from which the business draws its resources. End-user - person using the product When identifying the stakeholders for a new system, ask:’ Who will be affected by the new system? How will they be affected? Who will the end-users be? What are their needs? Utilitarianism - design the system for the greatest good for the greatest number of people. Failure to involve: End users must be involved in the analysis stage, otherwise the functions of the program might not match with the needs of end users, which might lead to a loss in productivity and waste everybody's time. Also end users might dislike the program and just not Advantage want to use it. Training and transition will be either a long process If end users are involved, they will take less time to adapt to the new system and training of the new system because they were or have more hurdles without involvement. Less ownership can lead to failure of the new aware of every stage of development system.  Data Collection Techniques Technique 1 Advantages ( 3 each) Disadvantages ( 3 each) Interviewer can clarify any Time consuming Interviews/ One to questions if needed If unstructured , the data yielded can be hard one meetings Interviewer can observe verbal and non-verbal behaviours of to organise and evaluate Interviewee may not be as comfortable interviewee giving honest answers Interviewer can observe emotions through hand gestures and facial expressions Technique 2 Advantages ( 3 each) Disadvantages ( 3 each) Direct Observation/ Different types of data can be collected Time consuming People may change behaviour if they know investigating Independent of user bias they are being observed The analyst spends more time The "Hawthorne Effect" may occur. This documentation familiarising and understanding means that the workers will work better the study when they know they are being observed Technique 3 Advantages ( 3 each) Disadvantages ( 3 each) Can remain anonymous, therefore Time consuming to set the survey to Survey/ the surveyed person feels more collect all the required information comfortable with stating the truth Some open-ended questions may be questionnaire Data is easy to collect and organise, especially if there are many harder to analyse Surveyed person can take their time when multiple choice questions doing it, leaving more accurate answers. Guarantee uniformity of data Data analysis is more straight forward  What is prototype Prototype - preliminary/simplified version of the product ( not used for testing of code, it is for test of the initial design) Why make them? See what technical difficulties can arise Attract investors Helps clients understand what the final product will be like Prototype Helps resolve conflicts between developers and stakeholders Prototype is used to ensure all essential functions/operations of the system are present/meets the needs of the users; Prototype is used to speed up development process; Positive user’s feedback helps in refining the acceptable prototype in order to develop the complete system/product; Iteration - Cyclical process that ends in a finished product - Process of prototyping, testing, analyzing test results, and refining product until requirements met - Allows constant improvement based on user or client feedback Situation where prototypes may not help Software developer works on a rather simple project / in a small company; No end-users so no need for feedback / to explore different possibilities; The software developer is the only end-user; No need to waste time and money on a prototype / to view how the solution might look; When designing very large/resources intensive systems; A prototype may be too expensive/ cost inefficient; In a case where trial/error is a dangerous approach/can be lethal/harmful for human lives/unethical; For example, systems that overlook nuclear power plants/ surgical equipment, etc. Accessibility Accessibility refers to the design In digital contexts, accessibility often involves making websites, applications, and content available to users with of products, devices, services, disabilities. This can include implementing features like: or environments so that they are usable by people with a Screen Reader Compatibility - Ensuring text, images, and multimedia can be interpreted by screen readers for visually wide range of abilities and impaired users. disabilities. The goal of Keyboard Navigation - Designing interfaces that can be accessibility is to create fully navigated and used without a mouse, which benefits users with motor impairments. inclusive experiences that Alternative Text for Images - Providing descriptive text everyone, including those with for images so they are accessible to users who can’t see the visuals. physical, visual, auditory, cognitive, and neurological Captioning and Transcripts - Adding captions or transcripts for audio and video content to assist those with disabilities, can easily interact hearing impairments. with and benefit from. Color Contrast - Using sufficient contrast between text and background colors to make reading easier for users with color vision deficiencies. Usability Usability is a measure of how Key aspects of digital systems usability include: Effectiveness - How well users can complete tasks effectively, efficiently, and accurately and achieve their intended outcomes. satisfactorily a user can Efficiency - How quickly users can perform tasks and accomplish their goals with minimal effort or wasted interact with a product, time. system, or service to achieve Learnability - How easy it is for new users to learn and start using the system effectively. their goals. It's a fundamental Memorability - How easily users can remember how to aspect of user experience use the system after a period of not using it. (UX) design that focuses on Error Handling - How the system helps users recover from errors, prevent mistakes, and navigate around making products easy and potential issues. intuitive for people to use. Satisfaction - How pleasant and enjoyable the experience is for users, encouraging continued use and positive engagement. Usability How Accessibility What is usability Usability means making the computer systems easy to use, matching them can be improved ( this and more closely to user needs and benefits everyone, people of requirements; determination and others) Accessibili Usability issues cell phone/ application Voice recognition; Text to speech; ty Has a small (touch-sensitive) screen; Uses batteries for power; Use of touch screen; Braille keyboard; (you must relate Screen contrast No hard disk drive / small memory; these with the Read aloud context of the Reliability / Network coverage issues; Zoom in question ) Too many/ illogical /complex steps to access a particular feature Inconsistent visual display ( colors and themes) Readability ( fonts and color contrasts) Efficiency ( slow, lagging) Usability and Accessibility of Website Usability Usability and Accessibility issues Complexity / simplicity / amount of Visual display design is not logical; workflows are not simple, and do not require as few effort to get a result / number of interactions as possible to complete; errors with the time taken to move Visual display design is not consistent; past them; navigation, header, footer, and main content Readability / Comprehensibility / are not always in the same places; Reading or writing speed; Visual display design is not usable as possible; tools are not easy to use, processes are not Learnability / time to accomplish broken down into logical steps; tasks on the first use; People with poor eye-sight/color blind can have Effectiveness ( user performance); difficulties to distinguish; because of the way graphics, words and directions are used / Efficiency (time needed to complete combinations of some colours (eg, red and green); a task); 1.2.7 - construct suitable representations to illustrate system requirements System flow charts - sequence of steps to solve a problem ( this is covered in this topic 1) processes , inputs , outputs and decision points, symbols of the system flowchart are below. Comprehensive overflow of the system( broader perspective) Data flow diagrams - data flow in a system ( this is covered in Topic 4), offer a more detailed view, encompassing the entire process flow, including decision points, actions, and dependencies. Structure chart - organization of a system (usually in form of a hierarchical chart) Example 1 Example 2 A bookshop has a computer at point of sale and also a central computer. When a customer buys a book in the book shop, the sales person at the point of sale uses a scanning device to input a barcode from the book. The barcode is sent to the central computer where barcode of each book and corresponding price are stored in a database on a disk When the price is found , it is sent to the point of sale computer where all necessary calculations are performed , details of the transaction are stored on the local disk and a receipt is printed. Example 3 Example 4 Customer orders are collected on A program accesses a text file on disk. To edit paper, keyed in, and stored in the the text the user of the program enters customer orders file. A stock master data using a keyboard. The program then file is searched to determine whether amends the text which was read from the file, sufficient stock is available, and an writes the updated file back to disk and appropriate report is produced. produces a printed report of all amendments Construct a systems flowchart made to the text file. representing the process described (a) Construct a systems flowchart representing above. this process