To be an artist means never to avert one’s eyes.
To be a consumer of P6 Primavera schedules means a nearly constant urge to avert one’s eyes.
Beauty is in the eye of the beholder, but the graphic produced by P6 is a schedule diagram only a mother could love. How did this come to be? Well, we have to start with the architectural basis on which the P6 diagram is built. All CPM systems have three engines: database, scheduling and display. Because of the algorithms that drive CPM, each change in the database requires a complete forward and backward pass of the database through the scheduling engine. Then a new set of early start dates is generated and redrawn.
Because the database is a column-and-row sort of affair, the user is unable to control the path of logic ties between activities. What results is a spaghetti dinner of logic ties presented in such a way that it is nearly impossible to follow which activity is driving which through the schedule. The graphical representation of the schedule could use some improvement, but mechanically, CPM is not up to the task.
Wouldn’t it be great if you could see how a building will come together day by day, based on all of your drawings and your schedule – to really visualize the plan? That might make a good blog url…
4D BIM can accomplish this, to a certain extent. If you ask most practitioners what the benefits of BIM and 4D BIM might be, they will respond with clash detection, more accurate cost information, and facilities management. These are the classic benefits of 3D BIM; the actual level of benefit derived from the implementation of 3D BIM has been quite variable.
But if the model is built correctly, you can see the risks in construction before the first piling is driven. For instance, you can see that your plan calls for two cranes to be in the same place at the same time, or that your plan calls for material to enter the jobsite through an opening that’s actually too small for the material.