Legacy system
In computing, a legacy system is an old method, technology, computer system, or application program, "of, relating to, or being a previous or outdated computer system."Often a pejorative term, referencing a system as "legacy" often implies that the system is out of date or in need of replacement.[2]
Legacy systems are usually still in use as opposed to retired (or archived) systems, which are no longer in use. Please remember this distinction.
SL version[edit]
Systems often interact with other systems. For example,
HL version[edit]
Real-world practical advice[edit]
Do you understand this material?[edit]
This is a simple example:
A small business has a computer kiosk inside the store which allows customers to sign up for a email newsletter. If a customer signs up for a newsletter inside the store, they will get a 10% discount on their first purchase at the store. The owner hopes this 10% discount will be an incentive for customers to sign up for the email newsletter. The business will then regularly email the customers special offers and savings. The business owner expects to benefit from this system by having increased sales. The customers expect to benefit from this system by having access to special offers, to save money, and to see what is new and trendy at their store.
Change request: The customers ask the business owner if they could also add their mobile phone number, as they would like to get a text message if the store is having a sale.
Question 1: Describe why we should carefully manage this change process.
Question 2: List the steps you would take to make this change (what would you do first, then next, then next).
Do you have an advanced understanding of this material?[edit]
A school of 900 students has a secure web-based application which manages attendance data. The school administrators carefully track attendance for the students so it can identify when students have been absent for a customizable threshold. For example, the school might set a threshold of 5 absences within 30 days, which then automatically notifies the student, parent, and teacher there is a problem with attendance. The threshold might be 3 times within 10 days, or something like that. The system keeps track of attendance and tardies. The system has customizable attendance codes. For example, "absence for school trip", "excused absence", "medical absence" are all allowed absence codes.
School administrators expect to benefit by having data about attendance so they can support students and parents to be in school. School administrators also expect to benefit by giving parents and students information about attendance (so parents can support their children to be in school). Finally, school administrators expect to benefit by using attendance data to apply for government funding (as they can prove how many students were in class on a specific day).
Parents expect to benefit by knowing when their children are in school or miss school. This way parents can support their children to be in school. Being in school is a shared value between the school and the parent.
Students expect to benefit by understanding how many days of school of they have missed. The school expects students to have a strong "ownership of learning" and manage their attendance.
Change request: a school administrator asks for a card-system, so students touch their id card to a reader and be automatically counted as present. There will be a card reader and camera in every classroom. Students must touch their id card to the card reader and then smile for a camera picture. the picture and information embedded in the card is stored in a database and used to provide evidence the student is present in class.
Question 1: Describe why we should carefully manage this change process.
Question 2: List the steps you would take to make this change (what would you do first, then next, then next).
Standards[edit]
- Outline compatibility issues resulting from situations including legacy systems or business mergers. Level 1