Mumbai University > Computer Engineering > Sem 7 > Software Architecture

Marks: 5M

Year: Dec 2015

Perspective Architecture

• A system’s prescriptive architecture captures the design decisions made prior to the system’s construction
• It is the as-conceived or as-intended architecture.
• Perspective drawing is a system of representing the way that objects appear to get smaller and closer together, the further away they are.

What Does Perspective Look Like?

• Imagine driving along a very straight open road on a grassy plain - the road, the fences and power-poles all diminishing towards a single spot far ahead of you.
• That's single-point perspective. Single- or one-point perspective is a simplest method of making objects look three-dimensional.
• It is often used for interior views or trompe l'oeil (trick-the-eye) effects.
• Objects must be placed to that the front sides are parallel to the picture plane, with the side edges receding to a single point.

One Point Perspective

• In one-point perspective, the horizontals and verticals which run across the field of view remain parallel, as their vanishing points are at 'infinity', with horizontals which are perpendicular to the viewer vanish towards a point near the center of the image.

Two Point Perspective

• In two point perspective, the viewer is positioned such that objects (such as boxes or buildings) are viewed from one corner, so that two sets of horizontals diminish towards vanishing points at the outer edges of the picture plane, while only verticals remain perpendicular.
• It is slightly more complex, as both the front and back edges, and side edges, of an object must be diminished towards vanishing points.
• Two-point perspective is often used when drawing buildings in the landscape.

Three Point Perspective

• In three point perspective the viewer is looking up or down so that the verticals also converge on a vanishing point at the top or bottom of the image.

Atmospheric Perspective

• Atmospheric perspective is not linear perspective, but rather attempts to use control of focus, shading, contrast and detail to duplicate the visual effect of near objects being crisp and clear, while distant objects may be less distinct and muted.

Descriptive Architecture

• A system’s descriptive architecture describes how the system has been built
• It is the as-implemented or as-realized architecture
• Descriptive analytics looks at data and analyzes past events for insight as to how to approach the future.
• Descriptive analytics looks at past performance and understands that performance by mining historical data to look for the reasons behind past success or failure.
• Almost all management reporting such as sales, marketing, operations, and finance, uses this type of post-mortem analysis.
• Descriptive models quantify relationships in data in a way that is often used to classify customers or prospects into groups.
• Unlike predictive models that focus on predicting a single customer behavior (such as credit risk), descriptive models identify many different relationships between customers or products. Descriptive models do not rank-order customers by their likelihood of taking a particular action the way predictive models do.
• Descriptive models can be used, for example, to categorize customers by their product preferences and life stage.
• Descriptive modeling tools can be utilized to develop further models that can simulate large number of individualized agents and make predictions.
• For example, descriptive analytics examines historical electricity usage data to help plan power needs and allow electric companies to set optimal prices.

Difference

• A descriptive process model describes what has happened in a software development.
• It is often developed as the result of a postmortem analysis.
• A prescriptive model describes what should be done during software development, including responses to error situations.
• The term procedure design is used in various situations.
• For example, in company procedure modelling the enterprise procedure design is often referred to as the company procedure design.
• Process models are primary ideas in the self-discipline of procedure technological innovation.
• A descriptive model is supposed to model how work is actually done, so it might go so far as to say "We do X when we think it has value" or "We tend to do Y on smaller projects and Z on bigger projects."
• Descriptive models have drawbacks; cowboy developers can ignore them and create risk.
• Prescriptive models, on the other hand, tell everyone exactly what to do and when. They tend to be large, require a lot of documentation, and are expensive in terms of person-hours to create.
• Prescriptive methodologies are essentially "project insurance"; your team pays a price of inefficiency now in order to mitigate or avert a disaster later.