The purpose of project controls has been defined as: Project controls are the data gathering, management and analytical processes used to predict, understand and constructively influence the time and cost outcomes of a project or program through the communication of information in formats that assist effective governance and management decision making.
The question posed in this short post is how can we fulfil this objective when different processes calculate completely different for the same set of project data? The options for the calculated project delay for the simple project outlined above are:
- CPM using progress override calculates a 3 week delay.
- CPM using retained logic calculates a 4 week delay.
- WPM and ES calculate a 16 week (4 month) delay.
Which option is correct or are all of the options correct and project managers are free to choose the delay they prefer to report? Full details of the various options are outlined in Calculating Completion: https://mosaicprojects.com.au/PDF_Papers/P217_Calculating_Completion.pdf [1]
My suggestion is a realistic prediction of completion needs more than a simple CPM update that assumes all future work will miraculously be completed as planned. WPM (Work Performance Management) has been developed to apply a similar approach to EVM, ES and ED, based on understanding the ratio between work performed and work planned and applying this factor to the future incomplete work to assess the likely completion date if nothing changes.
For more on WPM see: https://mosaicprojects.com.au/PMKI-SCH-041.php#WPM [2]