The process of improving systems
Statistical analysis is often an important part of long-term monitoring and improvement of the performance of a system. This process is often called continuous quality improvement and is particularly important in business and industrial contexts. The approach taken to solving many biological, agricultural and health problems can also be considered to be a process that is aimed at improving the treatment of a disease, the yield of a crop, etc.
The statistical part of the process again involves a feedback cycle of data collection and analysis, aimed at improving aspects of the system. The following diagram shows a common form of this cycle.
Data collection and analysis are an integral part of the Plan-Do-Check-Act cycle.
Example: Saving a native bird
A government conservation department is concerned about declining numbers of a native bird and funding has been allocated to try to reverse this trend. A small team is put together to utilise the funding, and the following is a description of what they did.
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The statistical process in other contexts
In many other contexts, a similar cycle is used to obtain 'improvements' in the system. For example, hospitals may be concerned that patients are taking longer to recover from heart surgery. What is the cause? Older patients, changes to surgical procedures, changes to care, ...?
The Plan-Do-Check-Act cycle can be used to determine reasons for the increase and determine ways to improve recovery times.
A Plan-Do-Check-Act cycle underlies most practical applications of Statistics.