A diagnostic system for determining and predicting service impacts to network connected applications. The diagnostic system stores static variables for each application in the network and receives real-time data for applications in the network. Each static variable comprises a processing time frame that is predetermined and considered an acceptable time for executing an application and a time threshold that is predetermined and considered an acceptable time for executing another application functionally dependent thereon. The real-time data comprise a time delay value for each application and is a measured time for executing an application. The system compares a time delay with a processing time frame for an application. The comparison result is used to determine a service impact for the application. The system predicts a probability of another service impact for a functionally dependent application using an algorithmic model, the service impact, and a time threshold for the dependent application.