Six Sigma in passenger transport

In the current competitive market, many transport companies offer the same services of person transport. The main distinguishing factor in front of users is, most of the time, the quality of these services. Six Sigma can help improve the quality in person transport.
Six Sigma is a data driven process improvement methodology based on DMAIC cycle (Define – Measure-Analyze – Improve – Control). Examples of measurable indicators for the specific activity of transport could be: time of travel; workload of the transport vehicle; specific cost of transport as example the cost per km; the number of passengers transported in a certain period; daily average distance, etc.
An example of a successful project using Six Sigma is "Increasing the number of passengers per day on the route x". The key indicator which give the performance of the process and choose to be improved is daily average of number of passengers (C).