One of the less well known benefits of location-based scheduling is that the quality of schedules is easy to evaluate. A well-planned schedule has certain characteristics that can be directly measured. During my year as a visiting scholar at Stanford University in 2005-2006 we developed together with master's students a list of attributes of a good schedule:

1) A good schedule should maximize productivity
~ continuous use of resources

~ durations based on accurate scope, quantities, resources, and productivity data

~ optimal crews

~ completely finishing locations before moving to the next location

~ aligned production rates

~ only one crew working in a location at the same time

~ good access and laydown space

~ right information and materials available

2) A good schedule should minimize risk
~ minimize the number of mobilizations

~ minimize the number of resources

~ buffers against uncertainty

3) A good schedule should be feasible
~ correct logic

~ resource constraints

~ accurate model of subcontractor behavior

~ coordinated with other subcontractors

Most of these issues can be directly observed from a flowline schedule. Continuous use of resources is the default planning option and can be seen as continuous lines in flowline. Durations require information about associated scope, quantities, and assumed productivity rates which can be checked against industry averages (such as RS Means in the US). Alignment of production rates can be checked by looking at empty spaces in the schedule - if a location is empty for a long period of time, the schedule is not well aligned. Overlapping lines in the schedule indicate multiple crews working in the same location at the same time. A linked 5D model can be used to evaluate access and laydown space. Location-based risk analysis tools show risky areas where more buffers are required. If the same risk assumptions are used for multiple schedules, the schedules can be compared quantitatively in terms of risk.

Vico has developed an internal scheduling assignment where all the participants solve the same scheduling problem with the same constraints and risk factors. The spread of results has been surprising. Using exactly the same assumptions for available crew sizes and exactly the same logic, the best submitted schedules have achieved three months faster schedules with lower risk than other submitted schedules which still follow the same constraints. This shows the power of schedule optimization but also that optimizing schedules is a skill which requires a different way of thinking compared to traditional scheduling where if the same durations and logic were used, everyone would arrive at the same result. If durations are allowed to vary as a function of crew size, and planners are free to optimize production rates based on resource availability and the overall sequence of locations within physical constraints, big differences in total durations emerge. It would be interesting to compare how well a CPM scheduler would manage using traditional CPM tools.

If someone wants to try this scheduling challenge, please contact me - I will send the files and instructions. I will also score the assignments and provide feedback as long as the total number of submitted assignments stays in reasonable limits.

If, like my students, you like to cram before a test, review these archived webinars:

BIM 401: Model-Based Scheduling

Scheduling Strategies in a Hard Bid

We also have a demonstration of Vico Control from Klorman Construction and a list for FAQs for Vico Control.  And here is a complete description of the Construction Scheduling Challenge.

Good luck with the challenge!