Lesson 1-Software Engineering for PRINTING

8/3/2019 Lesson 1-Software Engineering for PRINTING

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SOFTWARE ENGINEERINGPrepared by: Jerian R. Peren


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WHATISSOFTWARE?

Computer programs and associated documentation

Software products may be developed for a particularcustomer or may be developed for a general market

Software products may be Generic - developed to be sold to a range of different

customers

Custom - developed for a single customer according to theirspecification


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WHATISSOFTWAREENGINEERING?

Software engineering is an engineering discipline whichis concerned with all aspects of software production

Software engineers should adopt a systematic andorganised approach to their work and use appropriatetools and techniques depending on the problem to besolved, the development constraints and the resourcesavailable


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WHATISSOFTWAREENGINEERING?

In what order should these tasks be carried out to complete

the project in the shortest possible time?It is difficult to come up with a correct solution (or, solutions) without writing down possible options andconsidering them one by one (unless one comes with a built-in computer chip). It is hard to say why thisproblem is complicated, because no individual step seems to be difficult. After all, the most complicatedoperation involves adding small integer numbers.Software engineering is full of problems like this: all individual steps are easy, yet the overallproblem is overwhelming.


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WHATISSOFTWAREENGINEERING

Software engineering is often confused with programming. The role of software engineering isto capture the customers business needs and specify the blueprints for the system so thatprogrammers can implement it (Figure 1-2).

Software engineering relies on our ability to think about space and time,processes, and interactions between processes and structures.


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SOFTWARE ENGINEERING CONCEPT

To understand a complex thing, one needs to develop ideas about relationshipsamong the parts inside. By dividing a complicated job into simpler tasks anddescribing how they interact, we simplify the problem and make it easier tounderstand and solve. This is why imagination is critical forsoftware engineering (as it is for any other problem-solving activity!).


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SOFTWARE ENGINEERING


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SOFTWARE ENGINEERING CONCEPT

In a way, software development parallels the problem-solving strategies inartificial intelligence (AI):represent the goal; represent the current state; and, minimize thedifferences by means-ends analysis.


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WHY SOFTWARE ENGINEERING IS DIFFICULT

If you are a civil engineer building bridges then all youneed to know is about bridges. Unlike this, if youare developing software you need to know aboutsoftware domain (because that is what you are

building) and you need to know about the problemdomain (because that is what you are building asolution for). Some problems require extensiveperiods of dedicated research (years, decades, oreven longer). Obviously, we cannot consider such

problem research as part ofsoftware engineering. We will assume that the

problem is either solved (a theoretical solution

exists), or it can be solved in a relatively short amountof time by an informed non-expert.


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SOFTWAREENGINEERINGLIFECYCLE

Any product development can be expected toproceed as an organized process that usuallyincludes the following phases:

Planning/Specification

Design

Implementation

Evaluation


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So is with software development. The common software development phasesare as follows:

1. Specification / Requirements

- Documenting the usage scenarios and deriving the static domain model

2. Design

- Assigning responsibilities to objects and specifying the dynamics of theirinteractions under diffrent usage scenarios

3. Implementation

- Encoding the design in a programming language

4. Testing

- Individual classes/components (unit testing) and entire system (integrationtesting)

5. Operation and Maintenance

- Running the system; Fixing bugs and adding new features

The lifecycle usually comprises many other activities, some of which precede theabove ones, such as marketing survey to determine the market need for theplanned product. This text is restricted to engineering activities, usually undertakenby the software developer.


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SOFTWARECHARACTERISTICS

Software development is unlike any other productdevelopment in the following aspects

Software is intangible and hard to visualize

Software is probably the most complex artifact Software is probably the most flexible artifact

Lesson 1-Software Engineering for PRINTING

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