Guild of Project Controls: Compendium | Roles | Assessment | Certifications | Membership

Tips on using this forum..

(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?

(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.

This study is “Scheduling Practices and Project Success” by Dr. Andrew Griffith, PE.

1 reply [Last post]

This is a publicly available article from the Guild Library...

This study is “Scheduling Practices and Project Success” by Dr. Andrew Griffith, PE. 

This study looks at a variety of capital process industry project schedules, focusing on the practices used during schedule development with four measures;  cost performance and schedule performance related to industry benchmarks, cost growth over baseline budget, schedule slip over baseline schedule.  The data analysis identified four project schedule characteristics that correlated with “positive and significant project outcome metrics”; integration of all phases into a single schedule, application of CPM, resource loading of the schedule, and detailed review of the schedule by the project team.            


Rafael Davila
User offline. Last seen 3 hours 51 min ago. Offline
Joined: 1 Mar 2004
Posts: 5073

Unbelievably this is a paper published by the same organization that in one of their recommended practices is clearly against computer assisted resource planning because of Delay Paranoia.

  • Engineering calculations should not contain more “precision” than the level of accuracy of the input data. Anything reported in a more detailed manner than known from the inputs may be mathematically correct but misleading. This same principle also holds true for automatic resource-leveling of CPM schedules. Resource availability is not typically dynamically known nor modeled to exactly match the current  environment. Resource limits are seldom backed by adequate study and description (and in fact are often exceeded on construction sites.) The algorithms used to determine activity scheduling using resource constraints scientifically cannot be proven to be the most optimal.
  • This statement is false there is not such thing as an optimal schedule, there are hundred if not thousands of way to schedule the same job. If you give it to 100 schedulers you will get 100 different schedules, it is not an exact science. The contractor shall be able to plan his job in a reasonable way, not exclusively in optimal way, there is no way to determine optimal way, it is a catch 22 promoted by their RPs.  
  • Seems they do not understand resource limits can be real such as there is no place to fit 100 cranes on same building.
  • Seems they do not understand resource limits are used to reduce idle resource time, not merely to produce feasible but wasteful schedules. 

In their Delay Paranoia they pretend to create forensic procedures to be applied as if cooking recipes.

I enjoyed the article very much and would like to se it expanded to the application of approaches such as Critical Chain and Statistical Analysis that promote targeting for an early schedule to increase probabilities of success.