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Baseline Comments Received

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Radhakrishnan Nair
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Baseline Comments.

Some of the comments for a baseline are listed below. Appreciate your comments.

1. Project Milestones. Is it compulsory to have successors to milestones.
2. Restriction of maximum duration for activities to 20 days. Some long lead items are 50 days or more. How to cut short. Any hard and fast rules.
3. Key Milestone Should have zero float.
4. Restriction / limit of total number of critical activities. Maximum % allowed in comparison to total number of activities.
 

Regards,

Krish 

Replies

Radhakrishnan Nair
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Dear All,

Thanks a lot for all your invaluable feed backs. As observed most of scheduling practices can be improved only through such feed backs received like this from experts.

Cheers

Krish

Rafael Davila
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http://www.alphacorporation.com/49R-06.pdf

from page 2 of previous link:

Normally, there is only one critical path though a network schedule. There may be multiple critical paths through a schedule. Multiple critical paths may occur due to different paths having exactly the same overall duration. Constrained milestones (perhaps reflecting contractual requirements) may cause different paths to be critical at the same time. Individual schedules (each with their own critical path) may be combined into a master schedule that has a different critical path. In the case of a master schedule,there are both individual schedule critical paths as well as a larger program critical path. Project schedule specifications should define the legal interpretation of each type.

Another type of critical path is called a “resource critical path.” As there are rarely unlimited resources available to the project team the constraint of limited resources often strongly influences the critical path calculation. Therefore, in addition to the standard CPM calculations and logical connections, there is an additional, implied constraint of limited resources. In a resource critical path, after CPM network calculations have been made activities are further delayed, interrupted, or accelerated to reduce the overall daily unit resource requirement to some predetermined resource limit.

In some of our jobs, very common in government jobs, we have been required to use in our baseline schedules all available float or otherwise such baseline would represent a reduction in contract time for the overall as well as for the intermediate milestones as applicable. In such cases each contractual milestone shall display a critical path. 

It is not uncommon for the contractor to submit a distorted, unrealistic and different to true plans as to avoid war with owners that insist on such specification. At times we keep a set for claims purpose and to satisfy these kind of requirements and another to manage our jobs.

Fortunately use of buffers and statistical modeling is starting to be used more frequently, procedures I believe can allow for better scheduling without forcing the use of two separate sets of schedules. 

Mike Testro
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Hi Rafael

If you have multiple critical paths then the programme has been rigged.

Either deliberately or negligently by allowing the software to rig it for you.

Best regards

Mike Testro

Rafael Davila
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If you have several contractual milestones and all are required to have zero float or there is a possibility that eventually intermediate milestones will not be met you will get multiple critical paths. Same as when you make open ends critical.

Under resource leveling the number of critical paths can exponentially grow. Always keep in mind rules under resource leveling mathematical algorithms are different to rules under logic only.

There are no golden rules but guidelines that at times can be broken but always to be investigated why.

Mike Testro
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Hi Raharkrishnan

There are no such defined hard and fast rules in construction programming - common sense and practicality prevail.

1. Project Milestones. Is it compulsory to have successors to milestones.

What successor is there to a project Completion milestone? Some need successors - such as Power On - some don't.

2. Restriction of maximum duration for activities to 20 days. Some long lead items are 50 days or more. How to cut short. Any hard and fast rules.

The minimum task duration is good planning practice - long lead items can be an exception but even these could be broken down into sections such as manufacture - Shipping etc.

3. Key Milestone Should have zero float.

Again it all depends on the logical requirements of the programme - a section completion date would have total float against the project completion date.

4. Restriction / limit of total numnumber of critical activities. Maximum % allowed in comparison to total number of activities.
  of critical activities. Maximum % allowed in comparison to total number of activities.
 of critical activities. Maximum % allowed in comparison to total number of a
ber of critical activities. Maximum % allowed in comparison to total number of activities.

This is a nonsensical concept - the critical path is what it falls out to be. A better rule would be no more than 1 critical path.

Best regards

Mike Testro