The following is my answer to the subject question in a LinkedIn Project Management Group.

After over 35 years project management experience, I believe the standout is poor coordination between project tasks and the work (action) plans used by people to complete project tasks.

Where there is no explicit connection, variations in work plans are usually not picked up until a blowout occurs in the project task schedule.  Usually by this time, it is too late for the project manager to recover lost time. 

In many cases, work plans are in people’s heads.  Consequently minor slippages that when combined cause project task schedule blowouts are invisible to the project manager – until it is too late.

For the last 15 years, I have been focusing on refining a simple work planning template that lets people develop work plans in around 10 minutes.  The free work (action) plan template (available at www.taskey.com) is being used by thousands of people in over 175 countries.

I have found that connecting work plans to project tasks provides the early warning a project manager needs to be proactive.  In addition, Gantt chart progress can be automatically driven by actions actually completed.  This eliminates the need for an estimation of % complete.

At TASKey, we use TASKey TEAM software that can be accessed on both web and mobile browsers to manage work plans, to create personalized ToDo lists (for matrix management) for all project stakeholders, and most importantly, to collect in close to real-time the data a project manager needs to make timely decisions.