A project is, by definition, a once-off endeavor and in general many aspects of a project can obviously not be assessed statistically. The techniques mentioned above are therefore of limited value to manage quality in many projects. In the case of projects to design and develop engineering systems, several other techniques are generally used. Technical performance measurement (TPM) for example is a well-known technique that is much more appropriate to assess quality on system development projects than the overemphasized control chart but is unfortunately not yet mentioned in standards related to project quality management and is also underemphasized in other project management literature.