SEAM Lecture 5: Legacy Information Systems and Migration Planning

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Questions and Answers

Which term is used to define legacy systems as 'any information system that significantly resists modification and evolution to meet new and constantly changing business requirements'?

Cairo University Faculty of Graduate Studies

Bennett (correct)

Levels of Encapsulation

Oxford English Dictionary (OED)

What does 'Legacy' mean according to the Oxford English Dictionary (OED)?

Anything handed down by an ancestor or predecessor (correct)

A sum of money given by an ancestor

A type of software system

A method of software evolution

Which section of the SEAM Lec. 5 outline covers the topic of Constructing a Wrapper?

Legacy Information Systems

Software Evolution & Maintenance General Idea

Migration Planning

Levels of Encapsulation (correct)

What does SEAM stand for in the context of the provided text?

Software Evolution & Maintenance Signup and view all the answers

What is the main contact method provided for Tarek Aly in the text?

Email: tarekmmmmt@{pg.cu.edu.eg; egyptpost.org; gmail.com; yahoo.com} Signup and view all the answers

According to Bennett, what are legacy software systems?

Software systems that are large and vital but difficult to cope with Signup and view all the answers

What are some of the acceptable features of a legacy system mentioned in the text?

Runs on old processor Signup and view all the answers

What is the concept of 'wrapping' in the context of legacy systems?

Encapsulating the legacy component with a new software layer that doesn't provide a new interface Signup and view all the answers

What is the purpose of a database wrapper in the context of legacy systems?

To integrate a new component with the legacy system by involving both legacy data and queries Signup and view all the answers

What is the primary drawback of the wrapping technique for legacy systems?

It does not solve the problems with legacy systems Signup and view all the answers

What do forward wrappers in database wrappers involve?

Adding a new component to a legacy system by involving both legacy data and queries Signup and view all the answers

What is the purpose of backward wrappers in database wrappers?

To develop new components that use new data and access them via wrappers Signup and view all the answers

What are some common characteristics of a legacy system mentioned in the text?

Degraded structure following years of modifications Signup and view all the answers

'Wrapping' in the context of legacy systems involves communicating with the legacy component through which of the following?

Sockets, remote procedure calls (RPCs), or predefined application program interfaces (API) Signup and view all the answers

'Wrapping' is viewed similar to what in terms of providing service required by a client?

'Wrapping' provides service similar to a remote server; it provides some service required by a client that does not know the implementation details of the server. Signup and view all the answers

'Wrapping' captures outputs from the wrapped entity, restructures them, and pushes them to which entity?

'Wrapping' captures outputs from the wrapped entity, restructures them, and pushes them to the requesting entity Signup and view all the answers

What did Dietrich et al. first introduce at IBM in 1988?

The concept of 'wrapping' in the context of legacy systems Signup and view all the answers

Study Notes

Legacy Systems

Legacy systems are defined as "any information system that significantly resists modification and evolution to meet new and constantly changing business requirements".
According to the Oxford English Dictionary (OED), "legacy" means "a gift of property, especially one given to a person or institution, or a quality or characteristic that is handed down from one generation to another".

SEAM and Wrapping

SEAM stands for "Software Evolution and Maintenance".
The topic of Constructing a Wrapper is covered in the SEAM Lec. 5 outline.
Wrapping involves communicating with the legacy component through an interface or API.
Wrapping is viewed as similar to providing a service required by a client.

Characteristics of Legacy Systems

Some common characteristics of a legacy system include:
- Resisting modification and evolution
- Inability to meet new and changing business requirements
- Acceptable features, such as maintaining existing functionality

Wrapping in Legacy Systems

Wrapping captures outputs from the wrapped entity, restructures them, and pushes them to the client.
The purpose of a database wrapper is to provide a bridge between the legacy system and new systems.
Forward wrappers in database wrappers involve reformatting data to meet the requirements of the new system.
Backward wrappers in database wrappers involve reformatting data to meet the requirements of the legacy system.
The primary drawback of the wrapping technique is that it can lead to increased complexity and potential errors.

Legacy Software Systems

According to Bennett, legacy software systems are systems that are "out of date, obsolete, or no longer supported".

History of Wrapping

Dietrich et al. first introduced the concept of wrapping at IBM in 1988.

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Description

This quiz covers topics related to Legacy Information Systems, Levels of Encapsulation, Wrapping, Constructing a Wrapper, Migration Planning, and Migration Methods as outlined in Lecture 5 of the Software Evolution and Maintenance (SEAM) course at Cairo University's Faculty of Graduate Studies for Statistical Research.