; product commercialisation is a time of integrated forward flow; product launch and post-launch is a time of review and decision-making. There is no clear division of activities into the stages. For example, in some companies product design specifications can be at the end of Stage 1, in others the beginning of Stage 2; the final consumer test at the end of Stage 2 or the beginning of Stage 3, and the market test at the end of Stage 3 or the beginning of Stage 3. The demarcation is set by the accumulated knowledge needed by the top management to take the critical decisions.