Kenya Hara in Designing Design, introduces us to the concept or re-design by providing the example of a glass. He argues that the closer you look at a glass as an object you are designing the more you lose your existing understanding of the object. At the same time you become "more keenly conscious of glassess than before... you understand glasses more realistically". So, the more you look at the object in detail; the more questions you ask about it, the better you understand its purpose, limits, and constituent parts.
As a designer you start asking questions to help you define your design approach: what type of glass are you going to design, what will its purpose be, what liguid is it going to hold, is it going to be alcoholic, non alcoholic, cold, warm, heavy, light, coloured, odourless, etc. who is going to use it, in what context, for how long? For example: is the glass you are designing going to hold milk to be used by a toddler, or will it be a vessel to welcome champagne to be drunk in a comfirtable business glass seat on a transatlantic flight? The answers to all these questions will help provide you with a clear brief for the design.
This design thinking approach reseambles User Centred Design, only UCD goes beyond the object/service to be designed and focuses on the user/consumer of the design output. Take e-commerce sites for example. We are all familiar with them, we use them on a daily basis to buy our grocceries, presents, or even financial products. But what if we were asked to design one? How would we approach the challenge? We could try to replicate what we already know using our existing knowledge and experience, or we could apply some design thinking and suspend our knowledge of e-commerce sites and start asking questions about the site's purpose, context of use, its users' goals, motivations, and tasks. So, what are going to sell through the site, who is going to use the site, in what context, what is is that they are lookign for, what is it they are concerned about, what information are they preperred to divulge, etc. Applying design thinking in the form of a UCD process provided us with the freedom to re-think the design object (site, software, service, tool, etc.) and approach it afresh and with the end user in mind. What is wrong with re-inveting the wheel then? Why not make it work better for those who are going to use it? I am not suggesting we ignore established solutions, just suspend our understanding and ask if we can provide a better solution for our clients and their users.