It is a set or arrangement of procedures or programs so that together form a single unit. A set of facts, principles and rules are classified and arranged in an orderly fashion showing a logical plan at the junction of the parties. One method, plan or classification procedure to do something. It is also a set or arrangement of elements for a predefined target in the processing of Information. This is carried out taking into account certain principles:

* Must be presented and understood the information dominance of a problem.

* Define the functions to be performed by the Software.

* Represent software behavior to consequences of external events.

* Break in a hierarchical fashion models representing the information, functions and behavior.

The process should start from the essential information to the implementation details.

The analysis function may be to support business activities, or develop a product that can be sold for profit. To achieve this goal, a computer-based system makes use of six (6) elements:

* Software, which are computer programs, data structures and documentation giving effect to the methodology or controls logistics requirements of the program.

* Hardware, electronic and electromechanical devices that provide computing power and features fast, accurate and effective (computers, sensors, machinery, pumps, readers, etc..), Which provide an external function within the system.

* Staff are operators or direct users of the tools of the system.

* Database, a large collection of information organized and linked to the system that are accessed through the Software.

* Documentation, manuals, forms, and other descriptive information that describes or gives instructions for the use and operation of the program.

* Procedures or steps that define the specific use of each of the elements or components of the system and its rules of operation and maintenance.

A System Analysis is carried out taking into account the following objectives in mind:

* Identify customers' requirements.

* Assess client that has the concepts of the system to establish its viability.

* Perform technical analysis and economic development.

* Assign functions to hardware, software, personnel, database and other elements of the system.

* Set the constraints of budgets and timing.

* Create a system definition that forms the foundation of all engineering work.

To achieve these goals requires having a great knowledge and mastery of the Hardware and Software, and the Human Engineering (Management and Personnel Administration), and database administration.

Objectives of Analysis

Identifying Needs: It is the first step of system analysis in this process analyst meets with the client and / or user (a representative institutional, departmental or individual customer), and identify the overall goals, analyzes the client's perspectives, needs and requirements on the timing and budget lines, marketing and other points that may help identify and develop the project.

Some authors tend to call this part ¨ ¨ Requirements Analysis and divide it into five parts:

* Recognition of the problem.

* Assessment and Synthesis.

* Modeling.

* Specification.

* Review.

Before meeting with the analyst, the client is preparing a project concept paper, although it is recommended that this be developed for client communication - analyst, as the client do so anyway would only be altered over the identification of needs.

Feasibility Study

Many times when undertaking the development of a systems project resources and time are not realistic for its materialization without economic losses and professional frustration. The feasibility and risk analysis are related in many ways, if the project risk is high, the viability of producing quality software is reduced, but must take into account four main areas of interest:

Economic viability

An assessment of development costs, compared to net income or profits from the product or system developed.

Technical Analysis

A study of features, performance and restrictions that may affect the achievement of an acceptable system.

Legal Analysis

Is to determine any possible infringement, violation or liability that may be incurred in developing the system.

Alternatives. An assessment of alternative approaches to product development or system.

The feasibility study can be documented as a separate report to senior management.

Economic and Technical Analysis

The economic analysis includes what we call, the cost analysis - benefits, means an assessment of the economic investment compared to the benefits to be gained in marketing and usability of the product or system.

Many times in the development of Computer Systems these are intangible and it is somewhat difficult to assess, this varies according to the characteristics of the system. Cost analysis - benefits is a very important phase of it depends the possibility of development of the Project.

In technical analysis, the analyst evaluates the system engineering principles and simultaneously collects information on the performance, reliability, maintenance and productivity features.

The results of technical analysis are the basis for determining whether to continue or abandon the project if there are risks that does not work, does not have the desired performance, or if the pieces do not fit together.

Modeling System Architecture

When we want to better understand what we're going to build in the case of buildings, tools, aircraft, machines, creates an identical model, but on a smaller scale (smaller).

But when that which is a software build, our model must take a different form, should represent all the functions and subfunctions of a system. The models focus on what to do in the system as it does, these models may include graphic notation, Information and System Behavior.

All computer-based systems can be modeled as a transformation of information using an architecture of input and output type.