Once ideas have been communicated and agreed upon, it's now time for you to collaborate with other parts of your organisation to build out a set of processes for people to follow; systems to automatically test their work (and in some cases check they've stuck to the processes); define what tools you should all be using, and why; and finally agree how everyone is going to all develop the skills and culture needed to continuously maintain everything that's been built.
DevOps is big on collaboration. So big in fact you could argue it's literally the reason the movement was started in the first instance, to bring about a change to how software developers and IT operators did their respective jobs. From a DevOps perspective this involved removing the walls and getting them to talk to each other about all the decisions being made about the software from the first lines of code to the moment it's put in front of users. Or put another way: make them collaborate.
As you collaborate with your peers and other departments you'll begin to detect a collective sense of things coming together and taking the same direction. When this happens you'll know it but more importantly, so will the business and customers even more so.
As DevOps engineers collaborating with other departments and bridging all the gaps will drastically improve the overall efficiency of the company (which the business will notice) and the quality of your software solution (which the customer will notice.)
Once we can communicate and collaborate together, we can start building systems. But what do we mean by systems?