ct. In addition to needing sophisticated, service-specific active and/or passive measurement infrastructures, SQM requires sophisticated analytics that can be executed on ONAP as DCAE microservices to quan- tify the customer impact of network events [TONA, MERCURY] and to detect abnormally poor customer experience [ARGUS]. SQM also requires detailed knowledge of how customer traffic is carried across the network(s), including across network layers. We refer to this as the end-to-end service path. The automation enabled by ONAP and associated event detection, correlation, SQM, and other analytics offers the ability to reduce OPEX by automating operational troubleshooting, mitigation, and repair actions. However, we can also improve customer experience, as automated troubleshoot- ing and repair will typically reduce the time that it takes to investigate and resolve an issue- thereby reducing customer impact. However, it is important to note that the effectiveness of ONAP will be governed by the effectiveness of the policies and analytics (microservices) that define the control loops. 15.2.3.4 VNF Change Management Networks are continually undergoing change-as new technologies are introduced, new features are deployed, and software bugs are fixed. These updates typically involve deploying new software updates or patches, or changing configurations-typically network wide. Before changes are rolled out, they are extensively tested, and then introduced in a small field deployment (first field applica- tion [FFA]). Once successfully soaked in the field on a small scale, the software update, patch, or configuration change will typically be rolled out network wide over a period of time. The process by which a change is deployed on a given network function (virtual or physical) is defined via a method of procedure (MOP) or workflow. The heart of the workflow is the changes that are to be executed on a network function-these may be software updates or patches, or configura- tion changes. But any change that is executed must