Reinertsen's landmark 1985 article in Electronic Business Magazine, written while he was a consultant at mckinsey. This article is historically significant for three reasons: it was one of the first publications to quantify the financial value of development speed, it coined the term "fuzzy-front-end" to describe the ambiguous early phase of product development — a term that became standard in the field — and it produced the widely-cited finding that a six-month delay in product development can cost 33% of a product's life-cycle profits. This "33% rule" became one of the most-cited statistics in product development management and is frequently attributed to the "McKinsey study."
The article's core argument — that development speed has quantifiable economic value measured through cost-of-delay — became the foundation of Reinertsen's entire intellectual trajectory, leading to developing-products-in-half-the-time, managing-the-design-factory, and ultimately principles-of-product-development-flow. It is widely credited with triggering the movement to shorten development cycles in American industry during the late 1980s and 1990s.