Early is the only way to save big $!
Well documented across many industries is the fact that the
design and the cost of the design both become "almost
frozen" just a very short way into the development project.
The specifics of each study differ slightly, but the range
is well bounded across studies. Approximately 10-25% into
the development effort as measured by the development cost/budget,
the product cost becomes 75-95% fixed. Typically, cross-functional
resources have not been seriously involved in a critical review
mode until approximately 35-50% of the budget has been spent.
At this time, the product design and product cost are "really
frozen" and some parts and materials are already on order.
Finding omissions and errors at this time requires drawing
changes, engineering change orders, and often reordering of
materials. This is much more costly than finding an error
before a solid model is built or software is coded.
This management science is often referred to as "the
shadow theory of cost management." It answers the question
"how big a shadow on product cost does the progressive
expenditure of development cost cast on the product being
designed." Before the 1980s, it was believed that the
manufacturing function was the primary determiner of product
cost. We now know that the engineering function is the primary
determiner of product cost. Independent reviews, especially
by cross-functional downstream persons that will ultimately
be involved in the manufacturing and release of the product,
pay big benefits.