System Life Cycle & Systems in Organizations PDF

1.1.1 – 1.1.6 System life cycle – stages through which the development of a new system passes through - Most systems begin with the analysis stage and continue with the design à sometimes it might be necessary to return to an earlier stage  SYSTEMS IN ORGANI...

1.1.1 – 1.1.6 System life cycle – stages through which the development of a new system passes through - Most systems begin with the analysis stage and continue with the design à sometimes it might be necessary to return to an earlier stage  SYSTEMS IN ORGANIZATIONS PLANING AND SYSTEM INSTALATION - New system is created in order to replace a system that is inefficient, no longer suitable, redundant or out-dated - Purpose of a new system is to increase productivity or quality, minimize costs - New system should reduce the errors or flaws of the existing one - Development of most huge systems – huge amount of time, effort, contains a lot of different stages - Computer system includes hardware, software, people and the immediate environment - Updating may involve training employees, changing the physical location of a server, firing employees - Planning should anticipate potential organizational issues such as lack of: § Guiding organizational and business strategies § Stakeholder and end-user participation § End-user ownership of system § Attention to required training § Various organizational issues, such as organizational culture § Attention to the design of tasks and jobs, allocation of information system tasks, and the overall usability of the system - Feasibility study evalutes and analyses a project and its potential T Technical feasibility E Economic feasibility L Legal feasibility O Operational feasibility S Schedule feasibility - Change management – various parameters, process of shifting individuals, teams, departments, and organizations à WHAT TO DO TO CHANGE MANAGEMENT - Successful change management guarantees that all stakeholders accept and embrace changes in their working environments - The goal – maximize benefits, minimize the negative impacts of change on individuals - Legacy system – old technology, hardware, computer system, or application program - Legacy system may still be in use because its data cannot be converted to newer formats - For example, NASA still uses legacy system because the system still provides for the users’ needs - Business merger – combination of two or more businesses entities - Main reason to merge is to reduce costs  - Four strategies for integration o Keep both information systems, and develop them to have the same functionality (high maintenance cost) o Replace both information system with new ones (increased cost) o Select the best information system from each company and combine them o Select one company’s information system and drop the other companies’ - Language differences greatly increase communication problems - Software incompatibility – situation where different software entities or systems cannot operate satisfactorily, cooperatively, or independently, on the same computer, or on different computers linked by a local or wide area computer network à Some apps work only on Mac and dont work on Microsoft - Business software can operate o Installed on a client’s infrastructure and premises o Hosted on dedicated servers that belong to a company that provides such servers - Locally hosted system –for larger and complex systems - Remotely hosted system – there is no necessary hardware equipment or where the administration wishes to outsource responsibilities for maintenance, support, backups, security... SaaS (Software-as-a-Service) or „on demand software“ - contemporary delivery method, allows software and data to be hosted and managed centrally on a remote data center - Users pay to access the services provided on a subscription basis - Solutions reside on the cloud - Need a web browser and a broadband Internet connection - Low initial cast and requires few investments in installation, maintenance and updating - Provides a scalable solution, since a company has only to adjust its monthly SaaS subscription - Supported by a wide range of desktop, portable and mobile services - Requires few IT personnel and all software updates take place far away from company’s premises - Considered a safe solution – applications and data reside in the cloud service - There is a possibility of data loss, if a SaaS provider goes out of business - Installation of a new system – during this process the old system will be retired and new system will take its place - Implementation method (conversion, changeover) – one critical decision when moving from an old system to a new one - Changeover – putting the new system online and retiring the old one TYPES OF CHANGEOVERS Parallel - The new system is started, but the old system is kept running alongside it - data has to be entered into both systems - Advantages: if the new system fails, the old systems runs a backup (no loss of productivity); outputs from the two systems can be compared to see if new one is running correctly - Disadvantage: running two systems is costly in terms of time and money Big Bang or Direct (immediate) - Old system is stopped and new system is started - Advantages: minimal time and effort, new system is available immediately - Disadvantage: if the new system fails, there is no fall back Pilot - The new system is piloted (tested) with a small subset of the organization, once it is running correctly and all bugs have been ironed out, it is implemented across the whole organization - Advantages: all features are fully trialed; if the new system fails, only a small part of the organization suffers; staff who were part of the pilot can train other staff - Disadvantage: for the subset of users in the pilot group, there is no backup if the new system fails Phased - The new system is introduced in phases as parts of the old system are gradually replaced with the new system - Advantages: allows people to get used to the new system; training of staff can be done in stages - Disadvantage: if the new system fails, there is no fall back for that part of the system - Data migration – transfer of data between different formats, storage types and computer systems - Usually takes place in an automatic manner so as to achieve efficient use of human resources - This happens when an organization changes, updates, or merges its information systems - Many problems may arise: Incapability of moving the information due to parameters such as incompatibility with the new system or non-recognizable data structures Data may be lost or not transferred due to incomplete data transfer data structures Data can also be misinterpreted due to incompatibilities, caused by the different conventions of each country concerning date, time, and measurements units 1.1.7 Various types of tesOng - can happen in different ways/phases - TYPES à data tes\ng, alpha tes\ng, beta tes\ng, dry-run tes\ng, unit tes\ng, integra\on tes\ng, user acceptance tes\ng, debugging - FuncOonal tesOng tests individual commands, text input, menu func\ons, etc. Confirms that they perform and func\on correctly according to the design specifica\ons - Data testing is when normal, abnormal, and extreme data is put into the system. Suppose that there is a program that accepts a student’s percentage in a math exam and gives a “pass” message if the number entered is greater than or equal to sixty; otherwise, it prints a ”fail” message. - Alpha testing is done before the software product is made available to the general public, normally, Alpha testing will be carried out by the company that develops the software - Beta testing includes comments and suggestions of users outside the company - Dry-run testing is conducted using pen—and—paper by the programmer, he examines the source code and determines what the output of a run should be - During unit testing, individual parts of the system are tested separately - During the integration testing, the entire system is tested at the same time to verify that all components can work together - User acceptance testing is used to determine if the system satisfies the customer's needs and in most cases is conducted on user premises before accepting transfer of ownership - Debugging is a systematic process of finding and correcting the number of bugs (errors) in a computer program VALIDATION AND VERIFICATION TO DATA INPUT - A way of ensuring data verification is through double entry VERIFICATION VS. VALIDATION SOFTWARE TESTING - Verifica\on is the confirma\on that a computer product meets iden\fied specifica\ons, - valida\on is the confirma\on that a computer product meets its design func\on or is appropriate for the intended use. VERIFICATION: Are we developing the system correctly? VALIDATION: Are we developing the correct system? VERIFICATION: Does the product comply with a specific regula\on or condi\on? VALIDATION: Does the product meet the costumer-needs? 1.1.8 Importance of user documenta\on - as programs/systems develop, they can become to complex for the user or rather there could be a conflict of interest between him and the developer - this is easily countered by proper external documentation (user manual) - External documentation is typically written as a separate document from the program itself, it is provided through various types of user-supporting documents such as a users' guide, software requirements specification document etc. - Internal documentation is the code comprehension features and details provided as part of the source code itself. PROPER INTERNAL DOCUMENTS INCLUDES: Appropriate module headers Appropriate comments Useful and meaning variable name Useful module, classes, methods and func\on headers Appropriate code indenta\on Appropriate code structuring Appropriate use of enumerated types Appropriate use of constant iden\fiers Appropriate use of data types defined by the user 1.1.9 Different methods of providing user documenta\on - User documentation can either be in a written or in an online form - Manuals can be provided online or offline, One of the advantages of online manuals is the potential use of multimedia features, they can also be printed & the advantage of a printed - manual is that it can be read without the use of a PC or an internet connection - Email support is a form of Online support, it is an asynchronous type of support and can be provided via an email address. Users contact the support team of the company to resolve any problems with the help of specialized technicians - Embedded Assistance or integrated user assistance, one example is when the user hovers the mouse over an icon 3 small text box appears with valuable help information. This kind of assistance is considered an excellent way to increase the usability of a software application. Embedded user assistance is context specific & task-specific - FAQ’S are listed questions and answers, all supposed to give users answers to a common set of problems and pertaining to a particular topic, commonly listed on an online forum - Live chat sessions are a type of real-time support that is extremely useful for emergency situations. A live chat technician will ask for the description of the occurring problem, and try to present a list of possible solutions, it can be done by phone call, live chat, or video call - Online portals/web portals can provide updated manuals, support pages, and FAQ pages - Remote desktop connections are a function that enables a specialized person to connect to the user’s PC across the Internet from virtually any computer. Remote Desktop will actually allow a specialized technician to take control of the user's PC as though he/she/she was sitting directly in front of it 1.1.10 Different methods of delivering user training - Self instruction/self-study - allows the user to learn in his/her own time, until he/she achieves mastery of the subject. Printed manuals, books, e-books or other resources such as video tutorials or online exercises can be used. Advantages: no tuition fee, your own time schedule, Disadvantages: lack of guidance - Formal classes - offer an interactive setting that promotes open and free discussion between students and the teacher (instructor), Advantages: direct communication, no technical barrier, exchange of ideas between students, Disadvantages: shy students may do worse - Remote/online training - allows participants to take part in high-quality courses from anywhere in the world provided they have a PC and Internet connection, it is accessible 24/7/365, Time efficiency and time management are valuable strengths of distance learning, some disadvantages can include a person not being skilled enough in technicalities or not having a PC SYSTEM BACKUP 1.1.11 Causes of data loss - Data loss is an error condition in which data is lost/destroyed due to a number of reasons - Causes & solutions: 1. Accidental deletion – recovery file software, 2. Administrative errors – need for care, 3. Poor data storage – restructure data organization, 4. Building fires – store data in more locations, 5. Closing program without saving the file – use of autosave features, 6. Comp. viruses – antivirus software, backups, 7. Continued use after signs of failure – Self- monitoring and regular backups, 8. Data corruption/errors in computer data – regular backups, 9. Firmware corruption – regular backups, 10. Natural disasters – store data in more locations & regular backups, 11. Outsider interfering – regular backups & need for a firewall & authentication methods, 12. Physical damage – regular backups, need for care, 13. Power failure – need for UPS (uninterruptible power supply) and regular backups 1.1.12 Consequences of data loss in a specified situation - e.g. medical records of a patient are lost, now his life is in jeopardy - in most cases, it is not this serious, but there are exceptions - e.g. a client books a hotel room online, and upon arriving the receptionist informs him there is no record of him booking it, now he potentially has to sleep outside or find a new hotel 1.1.13 Range of methods that can be used in preventing data loss - In order to prevent data loss, precautions such as these can be taken: *regular backup of files - *firewall installation - *data storage in two or more locations - * removed hard copies (printed versions of data) - *installation of an Antivirus program - *human error reduction/failsafe - *online auto save backup (iCloud, Dropbox) - Redundancy is the duplication of storage devices & stored data of a company system which intends to secure the stored data à failsafe system - for fast data backup or data storage, some commonly used things are: Diskettes, Blu-ray discs, CDs, DVDs, USB, they are also non-volatile - Failover system is a computer system which is on standby capable of switching to a spare computer system upon hardware failure, network failure, or any other type of error, such as software malfunction - Main difference between it and a switchover system is the amount of needed human intervention - Failover is usually automatic and requires little to no human care, when primary server fails the standby server is made primary - in a switchover system the primary & secondary system interchange their role 1.1.14 Strategies for managing releases and updates - aim of updates is to improve the product or just perform minor changes - from SMALLEST to BIGGEST changes: patches, updates, upgrades, releases - PATCHES - updating applications by fixing known bugs/vulnerabilities - UPDATES – adding new functionalities or fixing known bugs, free in most cases - UPGRADES – contain novel functionalities or characteristics as well as cumulative bug fixes - RELEASES – final, working versions of software applications 1.2.1 - COMPUTER HARDWARE: The physical elements of a computer à screen, CPU,… - COMPUTER SOFTWARE: A series of instruc\ons that can be understood by a CPU à these instruc\ons guide the CPU to perform specific opera\on - PERIPHERAL DEVICE: any auxiliary device that can communicate and work with a computer à printer - COMPUTER NETWORK: A set of computer systems that are interconnected and share resources, as well as data. 1.2.2 - The computer can assume several roles in networked world à as a client, server, e-mail server, domain name system server - A DUMB TERMINAL is a device that usually consists of a keyboard, a monitor, and a network card that is connected to a server or a powerful computer à depend en\rely on the computer - A THIN CLIENT is a rela\vely low performance terminal, which heavily but not en\rely, depends on the server to which it is connected - A CLIENT recives data via the network, whereas the SERVER has saved data on it and offers it to clients - AN EMAIL SERVER is the equivalent of a post office that manages the flow of email in and out of the network, checks that an email address is valid, allows users to access their email - A ROUTER is a networking device that accepts incoming quanta of informa\ons, reads their des\na\on address, and distributes them across networks, according to a rou\ng table or rou\ng policy à iden\fies the des\na\on of messages and sends them via appropriate route - A DOMAIN NAME SYSTEM SERVER asributes names to network addresses and therefore resolves names by assigning them to the appropriate network en\ty - A FIREWALL is a hardware or sotware network infrastructure that controls data flow access among network en\\es à used to offer protec\on and limit access to a network - A CLIENT-SERVER refers to a sotware network architecture system where clients request informa\on and servers perform tasks in order to provide the informa\on 1.2.3 IT SUBJECTS OF SOCIAL AND ETHICAL SIGNIFICANCE ARE: - Reliability – refers to how well an IT system func\ons. - computer failures cause data loss, \me loss, money loss, injury or even death - Integrity – refers to protec\ng the completeness and accuracy of data - data lacks integrity if it is incomplete, out of date, or has been purposely or uninten\onally altered - Inconsistency – problems may also arise if informa\on is duplicated in a database and only one copy is updated, causing inconsistency (e.g. telephone field) - Security - refers to the protec\on of hardware, sotware, peripherals, and computer networks from unauthorized access - Privacy – the ability to control how and to what extent data is used and disseminated to others - Anonymity – privacy becomes anonymity when, for instance, an individual uses an IT system to conceal his/her true iden\ty in order to cyber-bully another person, commit illegal ac\ons or crimes, hack a computer, … - Intellectual property – refers to ideas, discoveries, scien\fic endeavors, photographs, films, essays, and art work - The Digital Divide and Equality of Access – the growth and the use of IT systems have not developed at the same rate for everybody in all parts of the world, or in all areas of the same country - Surveillance – involves using IT to monitor individuals or groups of people either with or without(also a privacy issue) their knowledge or permission à governments,… - GlobalizaOon and Cultural Diversity – IT helps to diminish the importance of geographical, poli\cal, economic and cultural boundaries while speeding up the global spread of poli\cal, financial, sport and cultural news - IT Policies – policies are enforceable procedures and measures that promote the appropriate use of computers, networks, informa\on systems and tehnologies - Standards and Protocols – predefined technical rules and conven\ons that developers of hardware and sotware should follow à GIF, USB,… - People and machines – internet addic\on is a social impact - the use of AI military or law-enforcement situa\ons is also an issue of social concern - analyzes all aspects of the interac\on between IT and humans - Digital CiOzenship – which covers appropriate behavior in a digital world - Appropriate behavior includes using IT ethically, in a way that respects society, the law and does not expose any person to threats, danger, … 1.2.4 - Stakeholders – individuals, teams, groups or organiza\ons that have an interest in the realiza\on of a project or might be affected by the outcome of a project - The end-user – person who is going to use the product 1.2.6 - EXAMINING CURRENT SYSTEMS is a process that involves the detailed examina\on of the current system, analysis its func\ons and procedures, studying the business and system documents such as current order documents, logis\cs documents, and computer systems procedures and reports used by opera\ons and senior managers - LITERATURE SEARCH refers to the iden\fica\on, retrieval, and management of various sources in order to find informa\on on a topic - Modern informaOon systems should be planned to: Increase client trust Preserve brand strength Preserve organiza\on reputa\on Maintain corporate resiliency 1.2.9 prepeats Enhance organiza\onal piece - ITERATION refers to the repe\\on of a set of Instruc\ons for a specific number of \mes or un\l the opera\ons yield a desired result - It’s impossible to design a system or sotware that has no ini\al func\onal or usability problems  1.2.10 - For system to be successful, the analysis and the design must involve all key stakeholders including the client and the end users - Involvement, collaboraOon and acOve parOcipaOon à cri\cal because a project with poorly- defined stakeholder goals is unlikely to be successful - The developed system either solve a different problem or deal with issues that are outside of the project’s scope needs 1.2.12. Usability to meet customer e - Accessibility – potential of service, product, device or environment to serve and meet the needs of as many individuals as possible. High accessibility – many individuals - Usability – potential of a product, application, or website to accomplish user goals 6 - Ergonomics or human engineering – design of safe and comfortable products, systems or processes, specifically for people to acomplish user goal 1.2.13. Usability problems with commonly used digital devices - 8 quality components of usability: Complexity/simplicity, effectiveness, efficiency, error, learnability, memorability, readability, satisfaction - Some usability problems: mobile phone – small keyboard, too many features for some users. PC – excessive keyboard use may cause RSI, large screens cause eye problems, mouse hard to use for left-handed users.... 1.2.14. Methods that can be used to improve the accessibility of systems - Impairment – a loss or abnormality of physiological, or anatomical structure of function - Disability – any restriction or lack (resulting from an impairment) of the ability to perform an activity in the manner or within range considered normal for a human being Aspects to consider when evaluating the accessibility of an IT system: 1. Visual impairment – blindness and color vision. Solutions: braille input devices, touch type, speech output devices, braille display, changing colors 2. Hearing and speech – Solutions: replace sound signals with visual effects, subtitles 3. Cognitive problems and learning disabilities – Solutions: active participation, multi sensory experiences, strong interaction, positive reinforcements, individualized instruction, repetition 4. Mobility impairments, limited hand mobility, Parkinson’s – Solutions: pointing devices to press keys, mouth and head-sticks to control a PC, left-handed or right- handed keyboards for those who lack one arm, track balls, larger keyboards, morse code as a keyboard, sip-and-puff using air pressure to control morse code, speech- recognition, word prediction software 1.2.16. Moral, ethical, social, economic and environmental implications of the interaction between humans and machines - Artificial Intelligence is evolving very fast, however many are concerned that AI might lead to unpredictable and dangerous situations with no human control over them - Ethics framework – religion, society, profession, and family. Moral framework – individuals set morals - IT has increased the number of printed papers, which causes many environmental concerns. Electronic waste contains many dangerous chemicals which cause pollution. - The digital divide is unequal access to technology within classes of people