And if resources, financing and supplies have limitations then critical activities may be not linked at all.
Subcritical activities have small resource constrained floats.

yeah I’m also confuse with that matters....anybody there give some direction for that subject

Charlie
As much as I would like too I wont "Oscar" you.
My comments have nothing to do with the "ambience" or even the common practice here in Hong Kong or Asia generally.
The thread I am trying to explore is that when drafting a programme the contractors process must follow a protocol where that which is realistic is paramount. Whether that results in one or several critical paths will only be established as the drafting progrseses. The drafting of the contractors initial programme without Clients constraints save for the start date I believe is good practice, and establishes a realistic basis for a project. The subsequent comparison of what the Clients expectations are and what the Contractor believes is achievable is a fundamental criteria for establishing the risk of a project at the time of tender. In turn it enables a quantifiable estimate to be produced as to the plant, equipment and reduction in productivity required to comply with the clients requirements. In the worst case it enables the Contractor to apportion risk allowances for not meeting the clients requirements. i.e the inclusion in the tender sum for overun costs including but not limited to additional prelims and LD’s.
My concept of including contractors milestones ahead of clients milestones to sound the alarm bells early is again I feel good practical project management. It enables the contractor to react to a situation prior to having penalties imposed upon him. It is I feel much better for a contractor to accelerate activities at his cost to achieve the clients milestone or key date rather than having to spend the money after non achievemnt as well as paying LD’s. I am of the opinion that part of the planners function is to assist the project team in identifying delay trends, mitigating those delays and protecting the commercial viability of the Company.

While Charlie I appreciate you are aware of what you are trying to say I find it difficult to ascertain what that might be. The purpose I feel of this forum is to share our knowledge as best we can rather than hiding our experience from the eyes of others. I would welcome your advice as to whether my concept of planning is acceptable to a man of such experience as yourself, or whether you can advise where in your experience other methods have achived a greater reward for your employer.

While the method adopted in Hong Kong of milestones, key dates, IPS and NPV’s was adopted in the early 90’s for the airport core projects it was drawn from the international arena and relied heavily on methods and systems of project controls adopted in the worldwide petrochem industry.

For my sins I was heavily involved in discussions both with Govenment and contractors in the initial drafting of the programme provisions and the understanding of the programme provisions within the Hong Kong contracting market. I was able to offer hands on experience of these systems from the experience I had gained from utilising the systems with the likes of Shell in Brunei.

From the implementation of the above system in Hong Kong changes and developments took place but the core methods of project control remains and has since been adopted throughout Asia on many Govenment projects.

Notwithstanding the Clients inherent wish to control the funding and progress of a project I feel that the programme realities and achievability lay firmly in the realm of the Contractor and it is his risk at the end of the day. I would suggest that one of the skills of the planning engineer is to identify the risk to the Contractor such that the risk can be quantified. Indeed It is I feel this ability above all else that establishes the commercial viability of planning within a contractors management team.

As to your quest to be Planner Omno (sic) Universale I will leave this "Don Quixote" journey to you, I am happy being a simple planner in the ambience of Hong Kong.

Clive

Charlie
Here what you say about constraints being a factor in determining the critical path. Clearly the contract start and finish date are immovable constraints and the critical path should start on one and end on the other, unless you can complete the project early in which case there is no critical path with zero float, but a critical path ie the longest chain of events.
As for other mandatory constraints imposed by the client I will ignore them until I am sure my logic is correct from start to finish. Actually at the start of a programme drafting the only constraint I use is the start date. Then I see how long the project should take as a first pass and compare that to the clients required end date. If I am adrift by more than 10% I stop and have a serious review of whats driving the delay.
After I am happy with the programme I look at the other required area completion dates. Normally we would express these as key dates and they may or may not have LDs. If our programme cannot achieve them again it a heads up as to why.
I will set up an activity at the end of the string as say area 1 complete (finish milestone) I will then compare this with the constrained date given for area 1 by the client. Usually I will not constrain the programme by using the clients dates but build in some additional safety by constraining my own finish milestone. This provides some alarm bells before the clients date is met and LDs can possibly be avoided. Often this method adds invisible float unless the client really interogates the programme.
Here in Hong Kong we can constrain programmes by Key date constraints but not by constraining milestones which are more commonly used as dates for achievement under the IPS. IE if you dont meet the milestone you dont have LDs but also you dont have any payment until you do achieve it. The milestone is generally a cost centre constraint whereas a key date may reflect a zone completion enabling beneficial occupation or operation which if it is not achieved results in a quantifiable loss and is therfore easier to apportion LDs to.
Clive

based on the adopted definition of the critical path (i.e. zero float), then it is definitely possible to have more than one critical path for a particular project.

Sonia
I cant see a problem with having multiple critical paths I dont feel replanning to ensure only one is created is such a good idea.
Often a programme will have a critical path and subcritical paths. Part of the planning process is to see where the ball is and where it is going. Reviewing float = 0 and then float = 5 then 10 gives agood impression of whats happening
Clive

Hi Francis,

Critical path is the longest continuous path of the project, which decides the project duration. (Hence the activities of this path have zero total float). If mutiple paths in the network happens to be of same length/duration, then there can have multiple critical paths in the project.

But ideally in the baseline programme we keep only one critical path by re-planninga ctivites. However, during the monitoring stage we can have multiple critical paths, becasue of delays in activites (once an activity reaches or crosses its late dates, it becomes critical).

I think sub-critical path shud be something like secondary critical path - the network path just shorter than the critical path. Hence it cannot have zero float, but the float will be the difference of its length from the critical path’s length..(bcos, this path can afford to delay till critical path finishes!)

regards
Sonia

It’s not a term I use myself, so someone else may want to correct me, but as I understand it:
-A sub-critical path is identical in every respect to a critical path, other than the duration is less.
-Hence, total float of the SCP would be zero
-SCP would have an end date equal to end of the project (unless you had constrained other activitites within the project in a way which would set the total float to zero, in which case the end of the SCP could be anywhere)

Hello Francis

In addition to what Gary said, you should have defined what your critical path is... using planning software (e.g. P3) you could define it as "TF less than 0","TF equals 0", or most likely the longest path in your schedule..

Cheers!

Christian