Birkdale Computing

One of the largest information technology challenges that organizations face (both private and public sector) is integrating information systems, that is preventing them from telling different stories. Fundamentally there are three categories of information systems integration: Data Integration, Application Integration, and Presentation Integration. They break out something like this:

• In Data Integration the data originating from more than one source, often generated and managed under very different circumstances and environments, must be brought together and sense made of the “integrated data” in some way before it is presented for consumption by applications or end users. Different types of ETL or ELT technology are used to meet this challange.
• In Application Integration two or more computer based applications collaborate to accomplish a joint task of some type[i]. Typically, application integration requires some form of data passing between the collaborating information systems, usually in the form of messages. In this type of integration very different data sources can remain separate and integration is accomplished by one or more applications, but generally still before consumption by end users. Orchestration technology is used quite often in this scenario.
• In Presentation Integration information systems integration does not occur until the data gets all the way through to the end user. Different applications and their data appear to be integrated and work together because they share a common interface to their users. Sometimes little or no integration of persisted data is done. This type of integration is also called “User Experience Integration” because it is important for the goals of the organization hosting the user interfaces that they appear to be the same application and provide a type of shared experience, even when they front diverse applications. The data integration here is actually used to provide a consistent interface for users of the data and relies on integrated meta-data to do so. [ii].

Message passing and integrated meta-data, of course, are types of data integration patterns, so it can reasonably be implied that, at least in a most fundamental sense, all systems integration is a type data integration. Data integration is by far the more fundamental of the three categories of information systems integration.

Not that there are challenges that uniquely pertain to application integration. For example, which application gets precedence in the event of processing conflicts and how and when messages are physically routed back and forth between collaborating applications are examples of application integration. But without at least the most basic concept of data integration, there could not be any application integration, if for no other reason than the collaborating applications need to signal each other their intent and the completion of their tasks. To do this they need to share data and agree on its meaning. Once application integration gets above the fundamental level of an ACK and a NACK and meaning and content are passed in messages, some type of integrated definition of the data in needed. Thus, the need for shared metadata arises, and shared metadata is, of course, another type of data integration.

So to understand information systems integration we need to understand the data integration first.

[i] There is actually another category of integration, “process integration”, which by its nature focuses primarily on the collaboration of processes and activities in the business architecture of an enterprise. However, this category is orthogonal to the IT categories of integration. Today it certainly takes information systems integration to make business process integration work successfully. However, people have been working together and collaborating for a long time, way before there ever were computers.

[ii] We say “user interface” instead of “human interface” because an increasing number of the users of application interfaces are and will continue to be non-humans. Or at least not human as we know it today.