I have been a big advocate of the work that Jeanne Liedtka, a Professor of Management at the Darden Graduate School of Business at the University of Virginia, has done. Several years ago, I had the pleasure interviewing her co-author Tim Ogilvie on the Business901 Podcast, Transcription with Podcast link: Using Design Thinking for Growth.
I have used their work and highly recommend the three books below as they have become a staple of my work. These books serve as the foundation for my development of the process of EDCA or Explore-Do-Check-Act. I like to use this term; EDCA learned from Graham Hill to designate the Explore aspect of Lean. I view it as more of Design Type thinking content that allows for that collaborative learning cycles with a customer. Below with an attached PDF is the EDCA process in an A3 form which I call the Innovation E3. I would recommend before using it though on an actual project that you review the process of SALES EDCA developed in the Lean Engagement Team. SALES is an acronym; I use to develop the team and give a high-level overview of the EDCA process. It would be well suited for the managerial or team leader level while the EDCA A3 would be for the team itself. Let me know what you think of it.
Download Zip File with PDF & Excel Sheets of the Innovation A3