IB Comp. Sci. Paper 1 Notes: 1.1 (Systems in organizations)

System analyst looks at existing system and observes how it works through surveys or interviewing users, then makes an evaluation of the current system so he can propose a new and better system to be created, increasing productivity.

Without a proper plan on how to implement the new system once it's designed, change from an old to new system will not be successful. System Installation and Employee/employer training should be considered

When two businesses merge, it's a major issue to make their systems work together since they're most likely not the exact same. Issues include language differences, businesses not using same software environment, differing unit systems, and use of different versions of a system.

The software manufacturer can help with malfunctions and manage updates and maintenance.

Chance of having data security issues as software managers have access to info, and if host is in different time zone, maintenance may be inconvenient.

Run new and old system at the same time. Adv.: Old System acts as backup for new system, outputs for old and new system through testing, and staff can be trained to operate different systems and not both. Dis: Costly and time consuming

Run the system in only one part of business only Adv.: Only 1 department is affected if system fails, cheaper than parallel running, staff can be trained in pilot facility Dis: If system fails, work at pilot facility is affected and data loss can occur

Old system is replaced part by part by the new system Adv: Each component of the new system can be tested before installing a new part, and staff can be trained in stages instead of all at once Dis: If implemented part of the new system fails, there is no backup, and if new system is very complex, implementing it in parts may be difficult.

New system replaces old one "over night" Adv: Least Costly, No need for parallel running, and new system is automatically ready to run Dis: No backup if new system fails.

Incompatible file formats, incompatible data structures, changed character sets and units which could cause misinterpretation, and the new system may not support old data storage techniques.

Alpha testing (first stage where engineers who develop the system test it with similar data), Beta testing (second stage where real users test it with real data) White box testing (tracing data on paper as it proceeds through algorithm) Black box testing (putting in data and comparing with expected outcome) Debugging (using a debugger/automatic program)

User documentation is the document that explains the working of the system to the user. Usually involves Minimum hardware and software requirements, installation guide, how to start the system and use its features, screenshots explaining main features of the system, example inputs and outputs, explanations of error messages and troubleshooting guides, and contact info of developer of the system

Files supplied together with the system and can be accessed with a button in the system Adv.: Accessible at any time when using the program, gives general instructions on how to use system ,solving major errors. Dis: Can only be used after system has been installed, not before or during, often only deals with very general errors, and often lack search capability

Web service hosted by system's developer to provide user documentation Adv: Can provide more help than help files, can be continuously revised by systems developer to deal with the most occurring problems (FAQs), Often provide an option for live support/help from a human operator, and they often have search capabilities built-in so that users can easily search through them Dis: Useless without internet connection and live support doesn't work well if user can't explain their problem well

Paper manuals supplied together with the system Adv: Can be read by users before starting to work with the new system, always available and helps to install system Dis: Can be lost, often limited to a little booklet supplying little information besides how to install the system, and May not be updated everytime system updates

Users read a manual or watch a tutorial, or randomly do something in the system to figure out how it works; only suitable for experienced computer users as they are more confident to start using an unfamiliar system alone

Users learn from an instructor in a classroom who teaches how to use the system; useful for training large amounts of staff since it's effective and relatively cheap, but if classes are too big then there is little time to deal with individual questions/problems

one instructor trains a single user by being in the same room or by some kind of remote connection (Skype, chat); most effective way of training since it can be suited to user's needs and abilities, but very expensive compared to other types of training

Power out during storm, defective hard-drives, system crashes, and malicious activities by employees or outsiders/intruders

Example: A hotel recently implemented a computerized system to manage room reservations. Reservations can be made through the hotel's website or via phone. All the reservations with customer, room and reservation details are stored in a database. After a while one of the hard disks in the system fail. If the hotel relied on storing reservation details only on that hard disk, all the reservations would be gone now and the hotel would have no way of knowing who had a reservation or how much each of their customers owed. They would also be unable to make more reservations until a new hard drive is acquired.

By copying all sensitive information onto a second hard disk or CDs (something that's not in the current system), chances of data loss can be reduced significantly and data loss due to malicious activities can be prevented as well. In large companies like Google, information is often duplicated on servers separated by large distances and in different climates to reduce chances of data loss due to environmental causes like tornadoes or earthquakes.

In some cases, info. can also be printed out to be archived, like books, texts, important contracts or scientific papers. However, this can be expensive and can take up much space. Hard copies can also be lost or destroyed, such as in a fire.

System automatically checks for updates over the internet from time to time. If updates are available, they are downloaded and installed automatically. Adv: Updates get installed automatically, making it easier for inexperienced users, and software manufacturer doesn't need to contact every user about the update Dis: Requires internet and users may not be informed about major changes in updates

Software manufacturer contacts every user about the new update and supplies them with the installation package to be installed Adv: Users have more control on what updates they want to install and users can know about any major changes an update may bring Dis: Users might miss an update fixing security issues, they might not know how to install the update and they might harm system by wrongly installing update