When I managed Waterfall projects we were expected as a part of the project initiation planning to put together a risk mitigation plan. This consisted of listing the possible risks, their cost and impact and probability of occurrence. For each risk we developed a mitigation strategy. This is a great tool as far as it goes. But it may not fit an Agile environment as well. Requirements may change and project functionality with it. New risks may be created. In order to mitigate these new risks we need an Agile method to quickly assess the risks and estimate what would be required to mitigate them. This where the Agile concept of a spike comes in. Explain what a spike is, the two types and how you would use them