The epiphany of integration points is that they control product development and are the leverage points to improve the system. When timing of integration points slip, the project is in trouble.
—Dantar P. Oosterwal
Principle #4 – Build incrementally with fast, integrated learning cycles
Building Systems Incrementally
In traditional, stage-gated development, investment cost begins immediately and accumulates until a solution is delivered. Often, there is little to no actual value delivered until all of the committed features are available, or the program runs out of time or money. During development, it is difficult to get any meaningful feedback because the process isn’t designed for it, and the system isn’t designed or implemented in such a way that incremental capabilities can be evaluated by the customer. The risk remains in the program until the deadline, and even into deployment and initial use. This process is error prone and problematic, and typically results in loss of trust between the system builder and the customer. In an attempt to adjust for this, customers and systems builders try even harder to define the requirements and select “the best” design up-front. They also typically implement even more rigorous stage gates. Each of these solutions actually compounds the underlying problem. This is a systems-level problem in the development process, and it must be addressed systemically.
Integration Points Create Knowledge from Uncertainty
Lean systems builders approach the problem differently. Instead of picking a single requirements and design choice early—assuming that it is both feasible and will provide fitness for purpose—systems builders work within a range of requirements and design options (Principle 3) and build the solution incrementally in a series of short time-boxes. Each time-box results in an increment of a working system that can be evaluated by the system builder and the customer. Subsequent time-boxes build upon the previous increments and the solution evolves until it is released. The knowledge gained from integration points is not solely for the purpose of establishing technical viability. Many integration points can serve as minimum viable solutions or prototypes for testing the market, establishing usability, and gaining objective customer feedback. Where necessary, these fast feedback points allow the systems builder to “pivot” to an alternate course of action, one that should better serve the needs of the intended customers.
Integration Points Occur by Intent
Cadence-based integration points become the primary focus of the systems builder, via a development process and a solution architecture that is designed in part for that specific purpose. Each integration point creates a “pull event” that pulls the various solution elements into an integrated whole, even though it addresses only a portion of the system intent. Integration points pull the stakeholders together as well, a routine synchronization that help assure that the evolving solution addresses the real and current business needs, as opposed to the assumptions that were established at the beginning. Each integration point delivers its own value by converting uncertainty into knowledge—knowledge of the technical viability of the current design choice, and knowledge of the potential viability of the solution, all based on objective measures (Principle #5).
Faster Learning Through Faster Cycles
Integration points are an instantiation of Shewart’s basic Plan-Do-Check-Adjust cycle , and thereby serve as primary mechanism for controlling the variability of solution development.
The more frequent the points, the faster the learning. In complex systems development, local integration points are used to assure that each element or capability for the system is meeting its responsibilities in contributing to the overall solution intent. These local points must be further integrated at the next higher system level. The larger the system, the more such integration levels exist. Systems builders understand that the top-level, least-frequent integration point provides for the only true measure of system progress, and they endeavor throughout to achieve those points as frequently as possible. All stakeholders understand that when timing of integration points slip, the project is in trouble. But even then,this timely knowledge helps facilitate the necessary adjustments to scope, technical approach, cost or delivery timing needed to get the project tracking to revised expectations.
Learn More Oosterwal, Dantar P. The Lean Machine: How Harley-Davidson Drove Top-Line Growth and Profitability with Revolutionary Lean Product Development. Amacom, 2010.  Ward, Allan C. and Durward Sobek. Lean Product and Process Development. Lean Enterprise Institute Inc., 2014.  Deming, W. Edwards. Out of the Crisis. MIT Press, 2000.
Last update: 11 May 2014