Directions, arrows, pointers, etc… all contribute to finding your way. They point to certain places and things that could potentially lead you astray or guide you into a location of greatness. This same analogy works for website flows and site mapping. Sketching and outlining the process of execution can add to a great experience if the user understands how to navigate.
Example: You’ve created a flow for how your e-commerce site would work during check out processing, after purchasing a product. If you’ve overlooked the small things like emailing purchase receipts or same billing/shipping address options yet included unnecessary windows for advertisements; this would detract from the goal that you set forth for your user. Same for content architecture and product grouping. Do not make a small task for a user a large difficulty for them to accomplish. Frustration leads to unpleasant users and could be the demise of future business. So plan your flow and go with it!
Design with LIFE in MIND…