Application Integration - Business & IT Drivers

Design Patterns are finding increased use for its apparent benefits, i.e. when there is a solution for a common recognized problem, why reinvent the solution again, instead use the solution design that is expected to address the problem. However it is not a one size fits all, as there are a combination of factors that may influence the choice of the design and architecture. Enterprise Application Integration is a complex undertaking and it requires a thorough understanding of the applications being integrated and the various Business and IT drivers that necessitate the integration.

There are numerous approaches, methods and tools to design and implement Application Integration and it is always a challenge in choosing the right combination of design, tools and methods to accomplish the business need. Selecting the right design requires good knowledge of the problem on hand and the other related attributes that drives the solution. In this blog, let us try to identify various business and IT drivers that the architects need to understand well before making a choice of the design, method, tool or approach.

It is also worth understanding that these drivers should be considered collectively. While a particular tool or design might seem to solve the specific need, it might require certain other needs to be compromised. Thus it is a mix of art and science that the Architects need to apply.

Business Drivers:

• Business Process Efficiency - The level of efficiency that the business wants achieve through the application integration is a basic need that should be considered. Being a basic need there is a tendency amongst the Architects to neglect to have this documented and thus leaving a chance failure in this area. Knowing this will also be useful in validating the design through the implementation phases.
• Latency of Business Events - Certain business events are time sensitive and need to be propagated to the target systems within a time interval. Achieving a low latency integration may require tooling the components at much a lower layer of the computing hardware.
• Information / Data Flow direction - Whether the data or information should flow in one way or should it be a request / response combination has an influence on the choice of design. 
• Routing / Distribution - The information or data flow might be just a broadcast or in some cases, there have to be a response for each request. Similarly, the target applications may be one or many, which could be dynamic based on certain data combinations. These routing and brokering rules have to be identified to orchestrate the data flow appropriately.
• Level of Automation - End to end automation might require changes to the source and / or target applications. Alternatively, it might be a best choice to leave this to be semi automatic, so that the existing systems and related process may remain unchanged. An example of this could be participation of a legacy system which is likely to be sunset in the near term, in which case changes to the legacy system is not preferred.
• Inter-Process Dependencies - Dependencies between processes would determine whether to use serial or parallel processing. It is important to identify and understand this need, so that processes which can be processed in parallel can be identified and designed accordingly, so as to achieve efficiency.

IT Drivers:

• Budget / TCO - Any enterprise Initiative would be budget driven and the Return on Investment must be established to get the consent of the project governance body (or Steering Committee). The Choice of tools, design and the approach should be made considering the allocated budget and aiming to achieve a lower TCO (Total Cost of Ownership).
• Technology and Skills - It is also important that the design and architecture considers the technology in use in the organization and the availability of skilled resources to build and as well as maintain the integration implementation. Application Integration solutions require a continuous maintenance as either of the source or target systems or even the business processes are likely to undergo changes. 
• Legacy Investment - All enterprises will have investments in legacy systems as the technology obsolescence is happening faster than planned. It would be prudent for enterprises to explore opportunities to get returns out of such legacy investments where possible. The Architects shall consider this aspect while designing integration solutions and thus facilitate planned sunset of Legacy systems over a period.
• Application Layers - Integration can be achieved at various layers, viz. Data Layer, Application Layer, UI Layer, etc. The choice of the integration layer depends on various business drivers and an appropriate choice need to be made to achieve desired efficiency, latency and other needs.
• Application Complexity - An enterprise is likely to have a portfolio of applications within and outside to integrate with. The complexity of the applications would have a direct influence on the design and architecture of the integration solution as well. A thorough study and evaluation of the applications is a must to come up with a good integration solution.

As you know the above is not an exhaustive list and there are various other business and IT Drivers that need consideration. In addition, the quality attributes like security, availability, performance, maintainablity, extendability etc that need consideration in choosing a right design and architecture for the application integration solution. I would be writing another blog on Quality of Service (QoS) considerations for Application Integration solutions.