Continuous Improvement (also Kaizen or Total Quality): is a policy of constantly introducing small incremental changes in a business in order to improve quality and/or efficiency. This approach assumes that employees are the best people to identify room for improvement, since they see the processes in action all the time.
(Source: http://tutor2u.net/business/production/kaizen-quality-circles-continuous-improvement.html)

Cause and effect diagram (also called the “Fishbone or Ishikawa diagram”), a participatory exercise in the shape of a fishbone which explores the links between the effects and the possible causes of an issue.

Problem solving cycle: is a cycle of problem finding and solving in which you can learn knowledge in each step of the process. Once you have found the solution it can be implemented in your process.
(Source: www.pac-it.org.nz/resources/Problem_solving_cycle.pdf)

Check sheet: is a simple document that is used for collecting data in real-time and at the location where the data is generated. The document is typically a blank form that is designed for the quick, easy, and efficient recording of the desired information, which can be either quantitative or qualitative.
(Source: http://en.wikipedia.org/wiki/Check_sheet)

Flow chart: is a diagram illustrating the activities in a process. Flowcharts are a useful tool to use when improving a process, especially when you are planning to collect data or to implement a solution. They can also be used to document a new process or to compare an existing process with an “ideal” process. They are a good communication tool, by using standard symbols everyone will have the same understanding of the process.
(Source: Fundación COTEC, CENTRIM, IRIM, Manchester Business School, Socintec (1998) TEMAGUIDE. A Guide to Technology Management and Innovation for Companies. A research undertaken with support of the EU Innovation Program.)