How Does Best Practices (ITIL Based) Help in the Management of the SDLC?

Simply put... SDLC is a Lifecycle approach to produce the software or the "product". ITIL is a Lifecycle approach that focuses on the "service".

DevOps initiatives are working towards excellence and breaking down barriers throughout the delivery cycle and value stream. DevOps is the progression of the SDLC. If ITIL (processes and activities) are not integrated early in the lifecycle the developers will continue to hit a brick wall that results in frustrated staff, high cost and little value to the business.