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Contractor A has a large construction project in the middle of nowhere. The logistics route from the nearest available port to the workfront is >1,500km long and in poor condition, and will have to carry something like 200,000 tonnes of plant, equipment & material.
Contractor B is tasked with (among other things) upgrading this logistics route.
Both contractors will be working in parallel, and for the same client.
It is expected that Contractor A will be hampered by the state of the logistic route in terms of:
-width & axle load restrictions limiting the size of vehicles able to use the route
-potholes, poor sightlines, congestion, etc limiting the speed with which they can get deliveries to site (and assuming they are limited on total number of trucks, hence total tonnage of delveries per day)
-some river crossing potentially becoming unpassable during the rainy season
All of the above problems for Contractor A should be gradually alleviated as contractor B progresses through his circa 24 month programme of roadworks.
What I'm struggling with is how best to model this gradual improvement in logistics for contractor A?
I could model it using one or more special logistics calendars, showing a gradual increase in effective working hours, or ammending the productivty rates over time for delivery resources.
But neither of these options would give me a dynamic solution. -i.e. if/when Contractor B starts running late on his roadworks, there would be no impact on Contractor B's programme, without heavy manual adjustment.
Can any of you think of a way to model this dynamically?
(We're using P6 on this job, so if Spider or Asta has some brilliant functionality that will solve this for me, that would be interesting to know yet ultimately not much help)
Also, I'm struggling with how best to write the contracts to protect the client from getting claims from Contractor A due to Contractor B's poor performance, without being able to make a similar claim against contractor B. -It's quite possible that Contractor B could finish his roadworks on time, but if he did the bulk of the work at the back end of the programme, Contractor A could still be adversely impacted in the early phase.
Having a key milestone with LDs attached to every single road & bridge would be a bit much I think.
Appreciate your thoughts...
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Hi Gary
I would seperate the two contracts.
The Contrcator B road is presumably going to become the main access to the project so it would deteriorate quickly with heavy truck usage.
Both contractors would be disrupted and the likelyhood of cross claims would be high.
I would suggest that Contractor A install his own temporary haul route using laterite / gatch topping that can be readily maintained.
This would cost circa $10 mil - get a price to check it.
Temporary bridge crossings for the rivers at say $50k each.
You can then set a constant haul / delivery rate for the first 24 months of Contract A work and an improvement thereafter.
Penalties could be applied to Contractor B if he does not deliver.
It would also eliminate the inevitable contingency that both contractors will build into their price and programme.
Use calendars for the rainyy season stoppages.
Best regards
Mike Testro
Hi Gary
Interesting case. I would consider to divide the 200,000 tons in truckloads of each 17 tons /truck, say 12000 truckloads. Then I would divide the truckloads in batches and use cascading scheduling techniques to level the resources. Drivers and trucks.
I would opt for substations ( parking end rest places) along the 1500 km road. Use these substations as buffer stations to supply the correct materials at the ROS ( Required On Site) dates to match the construction activities.
So you have difficult and good road conditions and you can estimate the duration of the rides. These are different and they are reasonable easy to predict and trucks could be different for the easy and difficult road conditions.
Use incentives and/or LD’s for the road completion up to the substations.
Trust this helps
Johannes
I don't know how trucks could help. If to model increasing supply of materials project may accelerate because more activities requiring these materials could be done in parallel. But what will change if more trucks will be used?
I suspected as much!
By delivery resources, i meant trucks / drivers
Gary, yes, Spider has the solution but it is natural to model limited material supply applying material leveling that does not exist in P6. What do you mean by delivry resources?
Email: PPadmin@planningplanet.com
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