1. A computer system for generating transaction tracking data that is used to simulate a customer environment or a test case scenario, the computer system comprising: one or more computer processors, one or more computer readable storage media, and program instructions stored on the one or more computer readable storage media for execution by at least one of the one or more computer processors, the program instructions comprising: program instructions to receive user input data, wherein the user input data includes, at least, an application topology constructed using a graphical user interface, wherein the application topology represents an application environment to be tested, and wherein the application topology includes nodes that are connected by edges; program instructions to validate the user input data for, at least, supported environments of components of the application topology, wherein each of the nodes are assigned properties that describe node attributes of the respective node, wherein the node attributes are selected from the group consisting of operating systems, middleware, and applications, wherein each of the edges are assigned properties that describe edge attributes of the respective edge, and wherein the edge attributes are supported protocols for transaction flow between the nodes; and program instructions to generate transaction tracking data based on, at least, the user input data, wherein generating transaction tracking data comprises decomposing the nodes into transaction tracking vertical correlation data, context data, status information, and timing data and generating, for each node, started events and finished events with specified context and timestamps reflecting the user input data, and wherein generating transaction tracking data comprises decomposing the edges into transaction tracking inbound events and outbound events with specified context and timestamps that are correlated to source nodes and destination nodes using horizontal correlation data.