For Review

[wandererdragon]

Criterias:
Does it have a lead? Does one paragraph flow into next?
Is the thesis statement clear? Did ypu essay stick to the thesis statement?
Are there any misconceptions?
Does the parer tell you anything new?
Is the topic narrowed enough? Is the subject adequately covered?
Did it tell story or three?
Did the essay keep the subsections clear and use parallel constructions?
Are the subtopics distinct enough?
Are all parallel constructions underlined?
Are there enough transactions to guide you though the logic, step by step?
does the essay feel carefully rewritten? Do any sentence wander?
Does the writer apper to know what he is taking about?

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Modeling System Techniques: Structured vs. Object-Oriented

Every moment of our lives we try to understand the world we live in and the processes we see and feel. So, we developed many different techniques for dealing with complexity around us like: metaphor, analogy, and abstraction.

The most scientific method of dealing with complexity is an abstraction. We create a simplified model of entity or process that contains only characteristics essential for our point of view. Now there are two major modeling techniques and both of them emerged from the computer world, and then spread to different areas.

The first of these two methods was derived from the structured programming by the Yourdon, De Marco, Gane and Sarson. All of them had the same idea but expressed it in different notations. The idea was that everything in the world is the part of one or more processes, so the main elements of the systems were processes. As I mentioned above this modeling methodology came from the computer world, and at that time the most used languages were procedural. As the result every system that was created at that time tended to be algorithmic with information flow from one process to another. This approach is called Structured Analysis and Design methodology.

But the progress never stands still. The object-oriented programming languages were introduced and brought new tools and way of thinking. As the result, scientists derived new methodology for dealing with complexity. The one of the most know approaches and techniques were developed by Booch, Jacobson, and Rumbaugh. These were Booch’s method, Object-Modeling technique, and Object-Oriented Software Engineering. These models consider the systems as number of components (objects) that interact with each other to deliver systems purpose, or behavior. This approach is called Object-Oriented Design and Analysis methodology.

Both methodologies evolved through time and now we can compare two main, mature representatives IDEF from the structured side and UML from the Object oriented.

IDEF notation is the most flexible from the all structured designs. The main element of the model is the process that is represented by the box on the structured diagram. This box has four different types of connections to the other objects and world. They are called inputs, outputs, controls, and mechanisms. The inputs of the process describe the resources. Controls regulate system and describe what to do with the resources. Mechanisms describe what will be used to produce outputs. Outputs are the results of the process. To summarize, we describe the system as the number of processes with corresponding inputs, outputs, controls and mechanism.

Different way introduces UML framework. UML’s structure elements are objects, classes, links, relationships, and use-cases, but it the designer or analyst can easily extend the UML vocabulary with its own definition, unlike in IDEF were the structure is nonexpendable. A system is represented by objects that interact with each other using messages send through links. The difference is that in structured modeling processes operate on data, while in object-oriented modeling data can behave by itself.

One of the main benefits of UML over IDEF is that it allows designers and to construct the system from the point of who is using the system and who interacts with it by developing scenarios if behavior. That effect can be achieved by using structured methodology, but will be difficult to model and implement. However, constructing the manufacture or fabrication system is easier with structured methodology.

In conclusion I would like to say that world is more complicated than any model we build, so there is “no right view.” Every view, or model gives us only one perspective on what we do. (600)