how to get from here to there
Once the discovery has been done and the strategy and appraoch have been vetted against time, budget and technological considerations the process of developing the documentation to define the experience begins.
The key issue here is that documentation must be developed that aids the process and clearly communicates what needs to be built. The needs of the development team are assessed and the resulting documentation is created solely to inform their process. Various artifacts (documents) such as site maps, use cases, experience flows and wireframes are then created and adapted to fit the needs of the team.
In parallel with development efforts, a valuable activity is to engage in prototyping of selected user experience flows and to test those prototypes in a rapid test framework (using clickable prototypes). This helps to inform the design and functionality as it's being developed and keeps things on track usability wise - user feedback constantly informs the design serving as a truing mechanism to keep implementation as close to the ideal user experience as possible.
Throughout this process stakeholder and team feedback is integrated as well to keep the user experience aligned with business needs.