Scheduling: Critical Chain Method

Something I didn´t found in PMBOK and Rita Mulcahy’s book about this method:

Critical chain project management uses buffer management instead of earned value management to assess the performance of a project.

Critical chain method adds the large amounts of safety time to activities in project buffers to protect due-date performance, and to avoid wasting this safety time through bad multitasking, student syndrome, Parkinson’s Law and poorly synchronised integration.

The identification and insertion of buffers:

Project buffer : inserted at the end of the project network. Any delays on the longest chain of dependant tasks will consume some of the buffer but will preserve the end date unchanged.

Feeding buffers: added to protect the activities synchronization.

Resource buffers: they are set to ensure that the appropriate people and skills are available.

Some notes:
Parkinson’s Law is the adage that “work expands so as to fill the time available for its completion”.

Student syndrome refers to the phenomenon that many people will start to fully apply themselves to a task just at the last possible moment before a deadline.

Yourdon Negotiating Games

High Level Planning has to be done during the initiating phase of the project.

Is this planning supposed to be ‘draft’?

Just in the moment you show this schedule, you can find yourself negotiating the project schedule with management. As you are at the beginning of a project, you probably still don’t have all requirements and you are not in position to define it properly.

Nevertheless, some stakeholders are going to wait for a final planning that would be according to the initial one. And it’s in this case when you can fall in some ridiculous negotiating games if you don’t explain clearly what means this draft schedule.

Very interesting how of some these games have been identified by Ed Yourdon.

Doubling and Adding Some
The project manager comes up with an estimate for the schedule and then doubles it. For good measure, a few extra weeks or months are then added in.

Reverse Doubling
Most managers are aware of the “doubling and adding some” game. They take the initial estimates from project managers and immediately cut them in half.

Spanish Inquisition
In this game, the project manager walks into a meeting unaware that he will be asked to provide management with an on-the-spot, instant estimate. Usually, the schedule has already been determined and the unwitting project manager is coerced into accepting it. When outsourcing software, competitors often are encouraged to match or beat the competitor’s

Low Bid
schedule in order to win the contract. Of course, the competitor’s schedule is not realistic, so the project manager must agree to match someone else’s folly in order to get the contract.

“Guess the number I’m thinking of…”
Management has decided what an “acceptable” figure is for the schedule but doesn’t reveal it. The project manager meets with management and attempts to guess what it is by starting with a realistic estimate and whittling it down until it reaches management’s ”acceptable” figure.

Rolling Wave Planning

Reading about Rolling Wave Planning I would like to remember some basic links that have been useful:

Now I have a question, sometimes when I try to use this technique, I have some problems because my sponsor challenges me for more details in the complete plan, and my plan finalizes being so accurate.

It help us to identify hidden tasks to be done and ensures the execution will be as we think.

Then, when the project starts and something changes the execution of the plan cannot be exactly as I planned, so the change of the project baseline is unavoidable.

How can I handle this situation?

Project Creep

Uncontrolled changes in a project’s scope or Scope Creep is a risk in most projects. It can happen by a big amount of reasons but the main it’s not being aware of it.

So, I would like to review some tips about how to take care about it:


  1. Scope Management starts before the project starts,
  2. Be sure you understand the project vision through the major deliverables,
  3. Understand the priorities of the stakeholders,
  4. Review the Change management process with the client.


  1. Define your deliverables and have them approved by your client,
  2. Break the approved deliverables into actual work requirements. Break it again till you be sure about there is nothing lost or defined wrongly,
  3. Break the project down into major and minor milestones,
  4. Evaluate the project schedule as a director visualize a movie before to film it,
  5. In this evaluation check that you achieve the deliverables,
  6. Be sure the Project Definition is completed and communicated to all stakeholders before you start your project. Once it’s done, get the approval.


  1. Expect that there will be scope creep. It’s there!
  2. Educate the project developers about change management processes,
  3. Document your efforts before you begin them,
  4. Ensure that all team members are aware of the agreed-to scope and have read and understand the scope as documented in the Project Definition.

Monitoring and Controlling

  1. Remain alert to small, nonessential changes the team may be making informally, thinking that they are delivering better service to the customer or increasing client satisfaction.
  2. Scope changes, even small ones, need to be evaluated in light of their overall worth and their impact on delivering results on time and within budget.
  3. A small change late in the project usually requires unanticipated, extensive rework in related parts of the solution.
  4. Keep on top of your issues. Many project changes will arise from project issues.


If you are alive about Project Creep in this stage of the Project, you did it! If not, you probably are delayed and you need to close faster than desired.

Reach: SIEF Lead Registrant

Be a Lead Registrant under Reach means leading all registration process/activity for a given substance.

To take into account:

  • Being Lead means High responsibility but no benefit.
  • A reason to be lead can be presented when they do not trust the others in the same SIEF.
  • When a party is a lead it remains the lead for ever!! It means for instance that if you are the methanol lead, every new importer/manufacturer needs to be guided by the lead.
  • If a participant has the largest volume, this party is just voted to be the lead if there is no one volunteering.
  • A reason to be Lead Registrant? because you own a lot of data and it can make the other to use it.
  • Initially the best option seems to be a dormant participant.

I need to continue investigating,