Common Layers in An Information System Logical Architecture

The following four layers are the most common layers in a logical multilayered architecture for an information system with an object-oriented design:

  • Presentation Layer (a.k.a. UI Layer, View Layer, Presentation Tier.)
  • Application Layer (a.k.a. Service Layer or GRASP Controller Layer )
  • Business Layer (a.k.a Business logic layer (BLL))
  • Infrastructure Layer (Data access layer, Persistence layer, Logging, Networking, and other Services which are required to support a particular Business Layer.)

Some common purposes of the above four layers are for example described in the book about domain-driven design at page 68-74, which is a book that otherwise is focused on describing the Domain layer

Sometimes there is no explicit distinction between the Business Layer and the Application Layer, e.g. the Application Layer is considered as being a part of the Business Layer. On the other hand, it is also possible to even further divide the Application/Business Layers into more layers. For example, if the Model View Presenter pattern is used, then you can consider the Presenter Layer as being a layer between the User Interface Layer and the Application Layer.

The Business Layer can also use a Business Infrastructure Layer (aka low-level business 'services' layer) logically positioned between Business Layer(s) and Infrastructure Layer(s). That layer (BI) is very general and can be used in several application tiers, e.g. a CurrencyConverter.

The Infrastructure Layer may be partitioned into different levels (high-level or low-level technical services). Though, it is not unusual that developers only consider the persistence (data access) and therefore only talk about the Persistence Layer or the Data Access Layer (instead of an Infrastructure Layer or Technical services Layer). In other words, the other kind of technical services are not always being explicitly thought of as being part of any particular layer.

Regarding that all types are not always considered as belonging to one particular layer, according to the "POSA book" (Pattern-Oriented Software Architecture A System of Patterns, page 39) a relaxed layered system (as opposed to a strict layered system) can use so called "shared data definition modules" which are types not belonging in a particular layer.

Famous quotes containing the words common, layers, information, system, logical and/or architecture:

    When a man says that he is Jesus or Napoleon, or that the Martians are after him, or claims something else that seems outrageous to common sense, he is labeled psychotic and locked up in a madhouse. Freedom of speech is only for normal people.
    Thomas Szasz (b. 1920)

    I think it’s the real world. The people we’re writing about in professional sports, they’re suffering and living and dying and loving and trying to make their way through life just as the brick layers and politicians are.
    Walter Wellesley (Red)

    The family circle has widened. The worldpool of information fathered by the electric media—movies, Telstar, flight—far surpasses any possible influence mom and dad can now bring to bear. Character no longer is shaped by only two earnest, fumbling experts. Now all the world’s a sage.
    Marshall McLuhan (1911–1980)

    There are obvious places in which government can narrow the chasm between haves and have-nots. One is the public schools, which have been seen as the great leveler, the authentic melting pot. That, today, is nonsense. In his scathing study of the nation’s public school system entitled “Savage Inequalities,” Jonathan Kozol made manifest the truth: that we have a system that discriminates against the poor in everything from class size to curriculum.
    Anna Quindlen (b. 1952)

    There is no logical reason why the camel of great art should pass through the needle of mob intelligence.
    Rebecca West (1892–1983)

    All architecture is great architecture after sunset; perhaps architecture is really a nocturnal art, like the art of fireworks.
    Gilbert Keith Chesterton (1874–1936)