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Prototyping

Prototyping is commonly a means for validating the software engineer’s interpretation of the software requirements, as well as for eliciting new requirements. As with elicitation, there is a range of prototyping techniques and a number of points in the process where prototype validation may be appropriate. The advantage of prototypes is that they can make it easier to interpret the software engineer’s assumptions and, where needed, give useful feedback on why they are wrong. For example, the dynamic behavior of a user interface can be better understood through an animated prototype than through textual description or graphical models. There are also disadvantages, however. These include the danger of users’ attention being distracted from the core underlying functionality by cosmetic issues or quality problems with the prototype. For this reason, several people recommend prototypes which avoid software, such as flip-chart-based mockups. Prototypes may be costly to develop. However, if they avoid the wastage of resources caused by trying to satisfy erroneous requirements, their cost can be more easily justified.

Model validation

It is typically necessary to validate the quality of the models developed during analysis. For example, in object models, it is useful to perform a static analysis to verify that communication paths exist between objects which, in the stakeholders’ domain, exchange data. If formal specification notations are used, it is possible to use formal reasoning to prove specification properties.

Acceptance tests

An essential property of a software requirement is that it should be possible to validate that the finished product satisfies it. Requirements which cannot be validated are really just “wishes.” An important task is therefore planning how to verify each requirement. In most cases, designing acceptance tests does this.

Identifying and designing acceptance tests may be difficult for non-functional requirements. To be validated, they must first be analyzed to the point where they can be expressed quantitatively.

Practical considerations

The first level of decomposition of subareas presented in this KA may seem to describe a linear sequence of activities. This is a simplified view of the process.

The requirements process spans the whole software life cycle. Change management and the maintenance of the requirements in a state which accurately mirrors the software to be built, or that has been built, are key to the success of the software engineering process.

Not every organization has a culture of documenting and managing requirements. It is frequent in dynamic start-up companies, driven by a strong “product vision” and limited resources, to view requirements documentation as an unnecessary overhead. Most often, however, as these companies expand, as their customer base grows, and as their product starts to evolve, they discover that they need to recover the requirements that motivated product features in order to assess the impact of proposed changes. Hence, requirements documentation and change management are key to the success of any requirements process.

Questions & Answers

feasibility study&fact gathering techniques
Nachi Reply
write about software engineering
Mandala Reply
8.10.0.
BARBU
define iterative model. example of iterative model. advantages and disadvantages of iterative model. when to use iterative model
Okello Reply
i try out in netbeans this code:public class Profile { private Profile(int w) { // line 1 System.out.println(w); } public final Profile() { // line 5 System.out.println(10); } public static void main(String args[]) { Profile obj = new Profile(50); } } It is the question 5, and the answer is 50
Jacqueline Reply
i need help....Discuss the factors that influence the choice of the software development methodology to use when implementing software projects?(20)
tatenda Reply
The success rate of software development projects can be increased by using a methodology that is adequate for the specific characteristics of those projects.  then the focus on RAD,XP,RUP.
Hemant
hemant hie...it is a presentation i am working on...can you help me wth the introduction....please a powerful one hahahahha
tatenda
yes
Hemant
Define and show all Dipthongs and vowels used in english phonetics
Okendro Reply
what is the software engineering
Axmed Reply
Please how can I create an application?
Eric Reply
please how can I create an application
Nchor
How do we create a software
Florence Reply
give a more direct question
Louis Reply
what is semantics?
amjad
what r the computer codes
Kawuba Reply
machine code, source code , object code, and byte code etc
Hemant
what is software
Manobendra Reply
a collection of program executable by code is called software
Hemant
how can I create a software
Mary Reply
use in any model . then after you create any software
Hemant
what is capability maturity model integration
Muctarr
what is maturity level
Muctarr
maturity level is organization's process improvement achievement in multiple process areas
Hemant
how to trubulshoot is configuration ?
priya Reply
hello
Julius
hello
abeer
hello
Sahil
hello
Natnael
Hello
Eric
Guy's put your answer only
Natnael
click start then click run then type msconfig then ok
Natnael
explain coco model
dawood Reply
it model based on LOC. i.e; number of lines of code.
Hemant

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Source:  OpenStax, Software engineering. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10790/1.1
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