The first is a graphic used to represent LAMDA as 5 things done concurrently to drive learning to optimal conclusions or decisions. The second shows that graphic placed into the context of the Decision-Focused Learning process taught in the last reference below.
The first mention of LAMDA outside of Allen Ward's training materials or Targeted Convergence's training materials was in the Prologue by John Shook and Durward Sobek to this book published posthumously:
A.C. Ward, Lean product and process development, The Lean Enterprise Institute, Cambridge MA, 2007, p XIII.
In the second edition of that book, Durward added substantial discussion of LAMDA into the core material:
A.C. Ward, Lean product and process development, second edition, The Lean Enterprise Institute, Cambridge MA, 2014, p75-80.
The LAMDA practices get extensive treatment as one of the key enablers of the larger set-based and "Success is Assured" practices in this book:
P.W. Cloft, M.N. Kennedy, and B.M. Kennedy, Success is Assured: Satisfy your customers on time and on budget by optimizing decisions collaboratively using reusable visual models, Productivity Press, Taylor and Francis Group, 2019. (see SuccessIsAssured.com)
Origins of the Term: the term LAMDA was developed as a part of Dr. Allen Ward's training materials on Toyota practices. To support that training, he created a small spiral-bound "Lean Skills Handbook" that was largely centered on LAMDA.
Definition: an acronym mnemonic for a collection of collaborative learning practices that Dr. Allen Ward observed as a major differentiator of the Toyota Product Development System. The acronym stands for "Look-Ask-Model-Discuss-Act": "Look" as in go to the place where it is and see for yourselves; "Ask" as in asking a variety of key questions to help uncover the key relationships; "Model" as in create visual models to improve the accuracy and efficiency of communication; "Discuss" as in pulling all the right people and expertise into the collaborative discussion around those visual models; and "Act" as in putting what you believe you have learned into action as quickly as possible so that you can then see the result, ask questions and adjust your visual models accordingly, furthering those discussions. Note that unlike many other similar acronyms (e.g., the PDCA Plan-Do-Check-Act cycle), LAMDA is not a series or cycle of steps done in succession, but rather a collection of things that should all be done concurrently. All LAMDA discussion should be asking questions around visual models or better around whatever it is in action wherever it normally is. When asking questions, you should be asking for visual models as answers, and then discussing what you see in those models. When you go look, you should be asking questions of the people involved, and capturing what you see and learn in visual models, which you should then discuss with the people involved to validate those visual models. Whenever you are in a meeting or other collaborative discussion or learning situation, you should be checking that you are doing all 5 elements of LAMDA.
Origins of the Practice: the collection of practices covered by the LAMDA term were in place in the 1980's and 90's, but had been evolving through Toyota's continuous improvement system for decades prior. Note that Toyota does not use the term LAMDA to describe those practices.