P6 Schedule Review- Best Practices & Filters

Hello all,

What are the best practices that should be considered when reviewing a P6 schedule from a contractor? Most especially when an heinous contractor (trying to manipulate) is involved.

All opinions shall be appreciated.

 

thanks

 

Bayo

Z
Zoltan Palffy 👤 Member for 16 years 10 months

you can run claim digger

you can set the previous update as a baseline and compare the varainces in column

F
Folahan Adebayo 👤 Member for 11 years 10 months

I appreciate all thoughts and suggestions.

Most important now is on how to easily spot/filter the difference in performance % btw previous and present DD.

Any idea on that???

Z
Zoltan Palffy 👤 Member for 16 years 10 months
  • All construction activities have at least one appropriate predecessor and successor. Only “Start Project” and the “End Project” are open ended.
  • ► Must use an appropriate WBS & Cost Coding Structure
  • ► Must include detailing, spooling and prefabrication to support construction installation.
  • ► The “As‐Planned” CPM network is based on conditions known on bid‐day.
  • ► Must be able to indicate work flows (crew movement requirements) and work packages
  • ► All work scopes are covered by at least one activity package. All necessary logic restraints are established within the schedule.
  • ► Can occur without interruption from other activities. If the activity will need to stop so that another trades can work, then resume; the activity should further detailed.
  • ► Can be measured (1000 LF of small conduit, or 400 LF of large cable, or 650 Light Fixtures, etc...).
  • ► Construction activity durations do not exceed 15‐21 work days.
  • ► Relationships are Finish‐to‐Start, or Start‐to‐Start AND Finish to Finish. SF relationships are not used.
  • ► Negative lags (leads) are not used.
  • ► Should be manloaded with direct labor manhours to forecast manpower requirements 
  • ► Should be cost loaded to forecast cash flow throughout the project.
  • ► Procurement, Submittals, Reviews, and material deliveries are identified.
  • ► Relationship Lags do not exceed the Predecessor Duration.
  • ► Weather sensitive work is properly assigned to a Weather sensitive calendar. Normal weather is programmed into the CPM network calendar.
  • ► Contract milestones are calculated using a Finish On or Before constraint so that backward pass calculations are properly determined.
  • ► Must include QA/QC activities as well as Testing and Commissioning.
  • ► Each activity is assigned to a responsible foreman.
  • ► Obtain input and gain formal commitment (buy‐in) from all project team members (foreman, superintendants, etc).
S
Syed Hussain 👤 Member for 13 years 7 months

Folahan,

While reviewing the updated schedule, the main foccus should be the critical path. Any delay on critical path will delay the project completion. You also need to check if some recovery plan has been incorporated to avoid any slippage on critical path. Contractor should be asked to submit a Modification Log with every schedule update to explain the changes and reasons of change.  I recommend you to run "Schedule Comparison/claim digger" for duration, percent complete, constraints, added/deleted activities and relationships and then compare the results with Modification Log to find any missing items.

If crashing technique has been used contractor need to submit a complete plan how duration of some certain tasks can be reduced. by engaging extra resources or working extra hours???

Float Burn Index (How quickly the float is being used) of non-critical activities should also be tracked every month. Higher value of FBI will increase the likelihood of a non critical activity become critical.

 

Syed

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Folahan Adebayo 👤 Member for 11 years 10 months

Hi Syed,

Thanks for your input and sorry that I didnt lay emphasy on Updated schedule which is actually the main focus.

Adding to your list, I usually perform the ffg while reviewing updated schedules:

- Run filter to check activities with illogical start or finish dates. No start activities in a future start date; nor completed in a future finish date

- Check to see activities with broken logic

- Look out for Lags manipulations

- Comparing longest path from previous DD and the present to observe the swing

- Indepth check of progress % on major activities (I am yet to find a filter or UDF to compare previous and present percentages easily: pls share if you have an easy way)

Hoping to have inputs from other experts in the house.

Bayo.

S
Syed Hussain 👤 Member for 13 years 7 months

Folahan,

 

Reviewing baseline schedule will be different from updated schedule. I usually run some filters to check some basic CPM requirements.

Activities without predecessor/successor--only start task should be without predecessor and Finish task/milestone should be without successor.

Constraints--- unless justified in Narrative. Only soft constraints should be allowed.

Negative floats--baseline should not have any negative float

longest path-- starting from project start task/milestone and ending at project finish task/milestone. Constraints may force to skip one or both ends.

lags/leads--Lags should not be used to delay the start of activity. Start of an activity can be delayed by using 'As late as possible' constraint or by inserting new task which will replace the lag. Negative lags shouldn't be allowed anyway.

SF relationship shold not be allowed as it produces reverese logic and need to be avoided.

check calendars are as per required working days.

Check if complete scope of work has been included.

sequence of events is in line with schedule specifications provided in contract/subcontract.

Experts, Please add if I missed something.

 

Syed 

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