Kanban Made Simple: Demystifying and Applying Toyota's Legendary Manufacturing Process

Although you may have skated on involving the entire team in the previous steps, don't do it in the design phase. By creating a design as a team you will increase buy-in and are more likely to create a design that addresses all the issues.
The team will be able to identify the roadblocks to the success of the program. A successful design will answer the team's concerns and questions. When the design achieves this objective, then you're on your way to a successful kanban implementation.
Also, consider the kanban a work in progress. As you operate the kanban and gain more information, make changes that will:
Improve its operation
Integrate in new information
Correct the loopholes that prevent flow
Don't be afraid to change kanban quantities when the calculated amounts do not let the preferred production sequence occur as planned.