Kaizen (Japanese for "improvement") focuses on continuous improvement in all the processes involved in business and management. It is the Japanese method of business management that the West has adopted. The 5 Ws are What, Why, Where, When and Who. This is the basis of the Kaizen philosophy.
Considering what the problem is and what should be done about it are ways of using this "W." Another way is to find what is good about certain processes and build on those good attributes.
Finding out why something happens is the focus of this "W." Explanations are required to establish why something occurred. It could be a good or bad thing but there is a need to know why; if it's good, it can be used again, and if it's bad, it can be changed or nixed altogether.
When did it happen or when will it happen? Establishing time frames is an important part of business. If there is something wrong with timing, then this step addresses the situation.
Where will it or did it take place? Was it a good location, and if it was not, has a lesson been learned so that location will not be used again? It could be that the location is not a good one for a particular project but perfect for another; this can all be established during the improvement process.
Who was involved, and finding out if they were the right people for the job, is another part of the process. Changing personnel and making sure the right people are in the right roles, teams and departments is a vital part of the Kaizen program.