Business object

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Business object ( English business object ) is a term used in object-oriented software development . Business objects are used to model real values ​​and processes in information systems . In addition to data, they also contain the logic for processing them (this is what distinguishes them from entities ).

task

Business objects build the bridge between

  1. the real or imaginary objects from the imagination of users of the software system and
  2. the objects of the information system.

advantages

If you build an information system along the structure of the business objects it manages, it is easier for users and software developers to understand. Due to the high degree of correspondence between the perceived reality and the structure of the software, users perceive such a system as "simple" and software developers can find their way around its development and maintenance more quickly. As a result, there are fewer mistakes, there are fewer misunderstandings and the faster development also reduces costs.

implementation

In object-oriented programming languages, business objects are implemented directly as object classes of the programming language. In older, non-object-oriented programming languages ​​such as B. COBOL or C can only be used indirectly for business objects. B. implement with the help of the CORBA standard of the OMG .

In contrast to business objects , technical objects represent the other or the remaining objects of information systems. Technical objects are e.g. B. the windows , controls and database tables that one needs to display and store business objects.

method

Software developers should first take care of correctly describing the business objects of their systems. They do this by creating an object model. An object model fulfills the same task as a technical drawing for e.g. B. a machine or a house.

Only when the object model is correct should software developers complete the software system by adding the technical objects.

An object model is correct if it meets all requirements. The object model fulfills a requirement when it meets all of its acceptance criteria. And it fulfills an acceptance criterion if the measurement that is described by the acceptance criterion leads to the expected result within the object model.

generalization

Domain objects are a generalization of the term “business object” . The word “ domain ” refers to the application area of ​​the software system, e.g. B. the control of a washing machine. In this example, it would be inappropriate to refer to the motor, the temperature sensors and the other components of the washing machine that are important for the software as “business objects”.

Delimitation to entities

Business objects are a further development of entities that was created around 1993 . They differ from the latter in that they are not limited to the database, but also contain processing logic (methods). It is often seen as advantageous to subordinate the entire processing logic of IT systems to the business objects.

example

Examples of business objects are the customers, products and orders of an order system. If the application system z. If, for example, 1,000 customers, 2,000 products and 3,000 orders are managed, then it contains a total of 6,000 business objects.

  • Situation : An order with 2 item lines. The first line of the article contains 5 computer monitors and the second line contains 10 computers. A monitor costs EUR 100 and a computer costs EUR 500. This situation contains 5 business objects: An order as well as 2 order lines and articles.
  • Action : The order is asked for its order value.
  • Expected result : 5,500 EUR.
  • Expected process :
    • The order asks the 1st line: what is your price per line?
    • The first line asks the article "Monitor": what is your price?
    • The monitor answers: 100 EUR
    • The 1st line calculates its price (quantity times price): 5 monitors at 100 EUR = 500 EUR
    • It returns this line price (500 EUR) to the order.
    • The order asks the 2nd line, which calculates its line price in the same way as the 1st line
    • The 2nd line returns its line price of (10 computers at 500 EUR =) 5,000 EUR
    • The order adds the two line prices and returns the sum (500 plus 5,000 =) 5,500 EUR

See also