Not enough people are involved early on the project. The more people you have involved the more likely you will detect errors. Executives are often brought in late to the project when their ability to influence its direction is small.
New Product Development: The more, the merrier
Over-involve is the new over-communicate
Typically when a group starts to work on a new idea, they tend to work out its feasibility in a small, tightly held team until they have a proto-type or at least a full-fledged business case and plan. At this point, they start to get the other functions involved to make the concept a reality. This is when the initial team first learns that the manufacturing process is untenable or the raw material costs are prohibitive or the design impinges on someone else's patent.
In every new product development improvement initiative I've ever worked on, we have identified the need to get all the functions involved upfront to work on the concept or prototype together. Yet because resources tend to be so stretched, we don't want to involve people from other areas on a concept that might not work out. Otherwise, we look foolish. The flip side of this is, of course, we could eliminate many more projects earlier on if we involved all the needed expertise at the beginning and thus decrease the total workload.
The critical success factor in developing new products is to detect the problems and errors as early as possible in the process. Getting as many people as you can involved early means there are more people who can test, theorize, research, and give input on how to improve the product and, hence, enhance its chances of success. Even getting customers involved in the development process greatly improves the product quality. Yet, because we don't want to look foolish, we often wait until we've "perfected" our concept before we popularize it.
The higher, the better
A corollary to The More, The Merrier to also get the involvement of the executive team early on in the development process. Usually, executives don't review new product plans until the plans or prototypes are fully fleshed out. This is for the same reason as above. They are very busy and don't want to waste their time on projects that won't pan out. However, to paraphrase Chris Meyer at CalTech, the level of senior management involvement on a project increases over time as their ability to actually influence the project direction decreases. These are the people who know the most about the direction of the company and about past experiences and the people whose support of a innovative new product is most needed.
This is just another reason to make sure that your company is not working on too many projects at once. Your leadership team can only attend to a finite number of projects.