Re: Application logic and Business logic

From: Alfredo Novoa (alfredo_novoa_at_hotmail.com)
Date: 02/28/05 

Date: Mon, 28 Feb 2005 12:54:27 +0100

On 27 Feb 2005 22:01:15 +0000, Patrick May <pjm@spe.com> wrote:

> The issue isn't GUIs or databases, it's the separation of
>application logic and business logic. Business logic, in this
>context, refers to the entities, rules, procedures, and processes that
>represent and define the core functionality of the business. Concepts
>like purchase orders, customers, service provisioning, and billing
>fall into this category.
>
> Application logic, on the other hand, relates to the way in which
>those business concepts are represented to users of an IT system.
>This category includes details like GUI features, report formats, and
>configurations to support non-functional requirements.

Agreed.

Using less words: business logic are database constraint and
derivation rules. Application logic is presentation logic.

> These two types of logic change for different reasons, on
>different time scales. In any large system, unnecessary change must
>be minimized. Separating these types of logic is just plain good
>engineering practice.

It is an essential practice, but unfortunately OOA/D does not separe
these types of logic and all is implemented in the applications using
low level 3GL code.

OOA/D is not aware of that there are specialized systems intended to
manage the business logic freeing the applications from such task.

These systems are called DBMSs.

I don't know any programmer who knows what a DBMS really is :-(

Regards