The successful integration of enterprise applications is usually affected by a number of factors; let's take a look:

• Proprietary data formats: Some of the applications use their own proprietary data formats with very little documentation on how to integrate with them, preventing integration between the applications or causing the application integration to be of poor quality, and therefore resulting in a number of issues.
• Data consistency issues: Maintaining data consistency can turn out to be a problem for EAI. When every application maintains their own data source, the consistency of data across the different data sources can turn out to be problematic, especially if the middleware is experiencing heavy loads, resulting in different versions of the same data to persist across the infrastructure.
• Performance implications: Inside EAI, a middleware is responsible for providing a glue between the different applications. This glue layer facilitates the transformation and transportation of data from one application to another. When a lot of applications are trying to communicate with each other concurrently, this middleware may see high loads impacting the performance of its routing and data transformation processes, causing an overall impact on the application infrastructure that might result in some slowdowns until the load on the middleware is reduced.
• Security issues: Since the different applications communicate through the use of a middleware, the middleware needs to make sure that the transportation of the data is secured from end to end. If even one endpoint is left unsecured, the whole application may see a security compromise.