Using skill priorities, only when regular time is no longer available overtime will be assigned.

Rashid,

You are right, there are many ways to skin a cat, and all work if by the end of the day the cat is without skin, I agree with you that different project requires different approaches, different activity scale. The software should not tell you how to model your job; it should provide enough options as for you to model your job the way is to be executed by your team.

The Batch Plant would have an activity of its own, perhaps a few activities. I would allocate the mobile units to individual activities as a single resource say Batch Plant Delivery with a maximum daily availability using partial assignments similar to the modeling of a crane.

If the Batch Plant can deliver 500 cm of concrete per day the production will determine how much to allocate to a particular activity. If activity A requires 200CM and activity B requires 150CM the partial assignment for A Batch Plant Delivery will be 200/500=40% and the partial assignment for B Batch Plant Delivery will be 150/500=30% so both pours can happen the same day and there will still be 30% available. Well I believe this is a close representation to reality that is practical and will follow resource allocation in a meaningful and transparent way.

This will not prevent you to assign the full fleet in the morning to pour A while at PM the full fleet will be pouring B. If you go by truck assignment then you might be in need to model shifts and these complicate things when shifts will vary on a daily basis.

UNLEVELED RESOURCE:


AFTER LEVELING:


Please note that because you are planning for sharing the plant on a daily basis by allocating a percentage of it to each pour on a single day you must set the duration of all Concrete Pouring equal to 1 day. For other resources you can set adequate partial assignments. Or if you prefer, you can create several activities properly tied to the start of the Concrete Pouring and then resource load them. Naming and how much detail will depend on your particular scheduling needs.

If you want to model the possibility of overtime at the Batch Plant perhaps using Skills with a skill priority to use regular hours’ skills can do the trick.

If you do not like this approach you can use material resources production and consumption. In this particular case I believe it is easier to model using partial assignments, for other situations the use of material resources might be better or perhaps the only option. If you are serious about resource usage and your software do not provide for the modeling and leveling of material resources and to model partial assignments better start looking for something better.

Best Regards,
Rafael

Rashid

I do not resource load the schedule with overhead resources that play no role in my resource leveling. Resources that might determine if an activity can be or cannot be performed, these I include. In our schedules crane use is not earnable as is not considered a deliverable, is critical and scarce resource that must be considered therefore no matter it is not earnable or billable it is to be included, the same with other resources.

The purpose of our schedules is not to make them substitute our billings, they are complementary and best used if WBS for activities is kept separate from BOQ, use of cost codes and cost centers allow us to show the details when required to model BOQ.

I always assign the resources to the activity they will be working on and in this way it is clear on which activity and the resource leveling will drive the activity and not any “parent” activity that might induce errors in my scheduling.

Using partial assignments my resources can be assigned to several activities a portion of the activity duration. Therefore a crew might be working at the same time on several activities.

I use multi-resources so I keep my crews and my detail on crew composition; I keep the best of both worlds.

I resource load my activities by assigning the crew at a click of the mouse and the individual resources will be automatically assigned no matter if two or a hundred resource types. Detailed crew composition allows me also to share resources among crews. For example my slab concreting crew is composed of concrete masons, formwork workers (borrowed as to make up a complete crew as required for the pour) crane, crane operator and a crew supervisor. I assign the activity for a full day but the crew composition is assigned differently, concrete masons and supervisor a whole day as to include finishing operations while crane, crane operator and borrowed formwork workers just 50%. Is very simple, is transparent and follows true resource leveling. I do not share resources among all crews but there are exceptions and slab concreting is one.

Resource details on crew composition do not prevents me from reporting crew usage without getting into the details.

Best Regards,
Rafael

Mike,

But hook up time for concreting, bucket up and bucket down, is not the same for slab concreting as for walls concreting, the pouring rates do vary, as for walls and flying-forms it is another quite different thing so you cannot model the crane usage based on quantity of lifts at a construction site, better use partial assignments.

Best Regards,
Rafael

Mike,

That CPM software cannot plan for crane usage and cannot warn you about over-allocations? This is new to me. In multistory jobs crane usage is critical, you cannot assign more activities it can handle.

Not every day the crane is doing the same thing, one day might be concrete slab pouring AM and PM on wall forms and wall concreting. Next day early am flying slab forms relocation to upper floor, and PM materials handling. Do not abuse laddering and lag it might backfire.

Best Regards,
Rafael

I am back, I was going out of the job on the second truck as it was 100% idle, having a few beers, don’t tell the PM he does not know when the trucks are idle.

Hey, there are 14 concrete trucks at the entrance waiting for the tower crane, the masonry subcontractor argue it was assigned to him for materials handling no matter how many activities were competing for the crane. Is on his CPM schedule.

Hi Rafael

So your excavation crews leave for a while and you send away your water trucks to bring them back again when required for another week or so?

What happens if only one crew is needed - then they have a whole truck to themselves.

The best method is to plan for excavation crew continuity.

Best regards

Mike Testro

Hi Rafael

Put your eartworks under a summary bar and add your water trucks to that - same as with a tower crane.

Best regards

Mike Testro

Hi Rashid,
the question was about resource overallocation.
Assigning crew INSTEAD of crew resources you may loose the information on individual resource usage and will not notice their overallocation.
If the crew EW A does some work and the Grader does another work at the same time the software will not show Grader overallocation (if only one Grader is available). So assigning some crew you shall assign all resources that belong to the crew. In other case you will not be able to get the reports on resource usage.
Best Regards,
Vladimir

There is no problem with the use of resource groups/teams, as a matter of fact anything more than 0 is considered to be a team, yes even a one resource team. When you assign a group, you are assigning many individual resources, same as with a skill or multi-resource.

The software performs resource leveling/constraining using the individual resources availability. If there are not enough individual resources available it will know and will delay activity execution until the team can be assembled.

Teams: Team is a group of resources that work together on the activity assignment.

These can be:

a) Resource Assignments
1) Renewable
2) Non-renewable

b) Multi-Resources Assignments

c) Skill Assignments

Resource Assignments: Resources are skilled human resources, equipment, services, supplies, commodities, materiel, budgets, or funds. Resources are used to perform activities in the project.
Renewable resources are resources available to be used after they have already been used on activity. For example, grader, crane, worker or driver. Non-renewable resources are resources that can be used on one activity and are consumed, therefore after all are consumed they are no longer available.
Multi-Resources Assignments: Multi-resource is a steady group of resources that can work only together. Thus, multi-resources can be assigned to an activity as part of one team only. Note this is particular of Spider Project as you can assign several teams to an activity.

Skill Assignments: Resources and/or multi-resources are organized as resource skills in case they can be assigned to the activity execution as alternatives even with different productivities, costs and other characteristics. When a resource skill is assigned to the activity execution, total quantity (or productivity) of comprising resources (and/or multi-resources) is specified. If you use named resources (Name+MiddleName+LastName+…) this is usually where they should be allocated.

All software handle these in their own way, some have more functionalities other less. Of course these functionalities can be wrongly used and then the results can be unreliable, it depends on the user.

Best Regards,
Rafael