In Primavera P6 Professional it is possible to work on multiple projects at the same time. The question then becomes how do you display the critical path of multiple open projects?
It’s good to note critical activities that cannot delay without negatively impacting schedule completion. But what about activities that are already behind schedule? These are your super critical tasks that require adjustment to meet project completion goals.
Project Managers are typically under great pressure to complete the project in as little time as possible. It is therefore imperative that project managers become familiar with the basic techniques to shorten the critical path and the many different ways to do this.
Read the post on Ten Six
Do you know how to track schedule costs in Primavera P6? Most of us are familiar with the process of updating and tracking schedule activity progress from a time standpoint, but what about the cost of those activities? Well, Primavera P6 has features available for keeping track of the cost of labor, equipment, and material resources. It is also possible to track the cost of project specific expenses.
This article describes the process of tracking the cost of labor resources on a project. It considers a schedule where all activities are on the critical path, so a delay in any activity will result both an increased activity cost and project management cost.
See the rest of the post in Tensix Blog here
When do you apply hard or soft constraints in Primavera P6? This is a question I had recently while working with a client and while there are no hard and fast rules as project specific circumstances can differ, here are some guidelines that may help. Many times the project schedule is influenced by certain constraints on the project. These constraints can be contractual, external, or internal.
As the most common form of Contract for an industrial facility is an EPC Contract, we refer to EPC contractors, isn’it?
This is a little misleading I believe… and offers an opportunity to unveil what I believe to be a systemic cause to EPC Project delays.
One could imagine an EPC contractor to be a company covering the whole range of activities for the execution of a Project, from the drawing board to the pipe erection at Site.
Such integrated model existed, up to the eighties, but has disappeared, Engineering companies having first cut their construction labour and equipment then their construction supervision.
The EPC Contractor one will find today is typically an association of two companies, one doing Engineering and Procurement (E&P) and the other one the Construction (C).
There are 3 types of associations between these two companies: a JV, a consortium or a sub-contract. The most frequent is the last one, the Construction contractor being sub-contractor to the Engineering Company, to which is awarded the EPC Contract.
Let’s look at the pro’s and con’s of each type of association to understand the paradigm leading to systemic delays in EPC contracts execution:
The Joint Venture seems the ideal: both parties share a common profit or loss. There is no conflict of interests.
The issue lies with how one party controls the costs charged by the other party. It is very difficult for an Engineering Company to control the manhours of manpower and equipment charged by a Construction contractor. The Construction contractor is likely to inflate the latter to make its own profit on these charges, regardless of the profit it could get from the JV.
The consortium has each party responsible for its scope, expenses and profit. This provides an incentive for each party to minimize its costs. There is a non recourse clause in the consortium agreement that prevents one party to claim to the other.
The issue lies with the impact that could be suffered by the Construction partner due to the delays in drawings and materials deliveries from the Engineering company. These delays will typically result in idle manpower and equipment. The Construction contractor will not be able to claim the resulting extra cost from the Engineering company. Knowing this, it will include such costs in its bid which will affect the price competitiveness of the consortium bid.
Finally, the most commonly found type of association is the sub-contract. The Engineering company sub-contracts construction activities to a construction sub-contractor.
The construction contractor is commonly paid applying unit rates to installed quantities, e.g. so much for a cubic meter of concrete cast, so much for a ton of pipe erected etc. This means that the construction contractor will be paid a fixed amount for a given amount of work done whatever its actual consumption of resources (manpower, equipment) is. In other words, the construction contractor bears its productivity risks.
The productivity of the sub-contractor is however highly dependent on timely deliveries of drawings and materials by the Engineering company. In case drawings and material deliveries are delayed, idle time of manpower and equipment will be suffered by sub-contractor, as sub-contractor will still be paid the same amount for each erected ton of steel and the manpower and equipment will require to be mobilized over a longer period.
In theory the sub-contractor could claim for such extension of time and related costs. Such claims are indeed made possible by the sub-contract type of association, contrary to the consortium.
In practice, the sub-contract usually contains difficult to match conditions to such claims. The claim might, for instance, be eligible only of there is a proven overall – not local – lack of workfront. The sub-contractor might also be required to prove that the delay impacts the schedule critical path etc.
As engineering and material deliveries are always subject to out-of-sequence and delayed deliveries, and the above claims are difficult to make, the sub-contractor will be careful not to mobilize too early. The sub-contractor will rather aim to always be a little under mobilized to achieve the best productivity.
On the other hand, the EPC contractor will not be fully transparent with expected engineering and material delivery slippage as its interest is construction progress rather than productivity.
Here, I believe, lies the systemic factor that leads to delays of EPC Projects organized under such contractual schemes.
As such scheme is the norm, one deducts that the owner is more concerned with price than schedule and has accounted float in its overall schedule for delay in the execution of the EPC Contract.
The scheme still entices the EPC contractor to complete as early as possible to avoid both Liquidated Damages and extra costs of prolonged presence at Site.
Oracle Primavera P6 offers two ways to define a critical activity in a project schedule. These are:
Which one you use depends on three things. 1. the setting you choose in the Project view’s Settings tab: 2. the setting you choose in the Schedule Options dialog, and 3. that you understand the difference between the two options. Primavera P6 defaults to the Total Float method.
This article is mostly about item three – what is the difference between Total Float criticality and the Longest Path? There’s some confusion about this in the industry because unfortunately the term “Critical Path” and “Longest Path” often get used interchangeably. In reality they are two distinct methods of calculating critical path and P6 can do either.
First, let’s take a look at the location of the settings for these two options in Primavera P6 Professional.
Critical Activity Definitions
Go to the Projects view of you Primavera P6 Professional application, select a project and then click on the Settings tab in the bottom layout.
You’ll see the default setting for defining critical activities in the area imaginatively named “Define Critical Activities”, in the lower area of the Settings tab.
This is the default behavior that will be offered to the scheduler when running the Schedule function.
However, this can be overridden at any time in the Schedule Options dialog, accessible from the Schedule dialog (accessed by clicking the F9 key or selecting Schedule from the Tools menu).
In here you select the Total Float less than or equal to [value in hours] or go with Longest Path.
Total Float vs. Longest Path
The difference between Total Float and Longest Path can be summed up in the following way. Total Float calculations look at the Total Float for each activity in the network. If its Total Float value is zero, then it will be flagged as a critical activity. However that doesn’t necessarily mean the activity is on the longest path; it just tells us that the activity is critical, and it may be so due to other factors.
The following example shows how the critical path appears when the Total Float method is used to calculate the Critical Path. Activity A1050 has a ‘Finish On or Before’ constraint that is equal to its planned finish date, so it and its predecessors are showing critical. If they slip, they probably won’t impact the end date of the project, but they will overrun their constraint date; which is why they are showing as critical from a ‘Total Float <= 0’ perspective.
However, if the method of calculation is used these same activities will not appear as critical because there is a constraint somewhere along that path. They will not in this case affect the end date of the project, so they are not on the longest path.
In this next example you can see the identical project schedule when it is calculated using the Longest Path method.
Previously critical activities are now showing as non-critical. Interestingly, they still have zero days Total Float, but P6 is ignoring them because they are not part of the longest path through the network.
The Longest Path through the schedule network will only consider activities as critical if they are on a contagious path from the start of the project to the end. Typically this is a single path upon which any activity that slips will impact the end date of the project.
Usage
Schedulers often use the Longest Path method when first developing the schedule. This gives them a clear idea of the activities that are driving the scheduled finish date for the overall project, without concerning themselves with complicating factors such as constraints, resource leveling, path divergence and convergence and other items that come into play when working a large and complex schedule.
Primavera P6 even has a “Longest Path” Boolean field that allows you to create a filter to see only activities on the longest path.
The Critical column and the Longest Path column will hold different values once a calculation of each type has been performed on the schedule at least one time.
With Primavera P6, you’re not committed to one method or another. At any time during the project lifecycle you can switch from Total Float to Longest Path depending on what you need to see. And at any time you can report on one or the other methods by using the Critical and Longest Path column values.0
