How LYNX-X plans your work

Summary: A LYNX-X plan made with the CCPM engine keeps its safety in buffers instead of in every task, measures progress by the time still needed instead of % complete, and orders the work by how each chain is using its buffer. Here is what each idea changes in your week.

Applies to

Definition

LYNX-X can plan a project with Critical Chain Project Management (CCPM), with Load factor or with critical path planning. This article is about the CCPM engine, which gives the fastest plans that are still feasible and is where most of LYNX-X's value lies. A new project uses it unless your space is set up otherwise: in the project's properties, on the Scheduling tab, Activate CCPM schedule engine is ticked.

The critical chain is the sequence of tasks that decides when a project can finish, taking into account both the order of the tasks and the people and skills available to do them. A delay on that chain threatens the delivery date. LYNX-X protects the chain with buffers: time held in reserve at the points where delays would hurt.

If you have planned in MS Project or a spreadsheet, three ideas work differently in LYNX-X.

Purpose

These ideas exist so that a plan protects its deadlines, shows early where it is in trouble, and tells everyone what to work on next. Knowing them before you build your first plan explains what you will see in LYNX-X: tasks that look short, buffer percentages and a list that orders itself.

Key concepts

The safety is in buffers, not in every task

Most estimates hold some safety, in case the work takes longer. In a LYNX-X project, a task can be planned at a shortened duration, with the safety taken out and pooled into shared buffers:

• a project buffer at the end of the critical chain, which protects the project's deadline;
• a feeding buffer where a side chain of tasks joins the critical chain;
• a milestone buffer before a deadline inside the project.

How much a project shortens its tasks is a project setting: in the project, Properties > Critical chain > Shorten durations by (%). A shortened duration is not less work. The assignment keeps the estimate, and the plan uses the shorter time.

For you: a single task's date is not the promise. The project's deadline is, and the buffers protect it.

Progress is the time still needed, not % complete

Whoever does a started task reports how much working time is still needed to finish it: its ETTC, Estimated Time To Complete, in Focus > My activities. LYNX-X recalculates the plan and the buffers from that number.

The reason is the same as a navigation system's arrival time: it is a forecast from where you are now, not a look back at what you have done. A percentage complete rarely matches the time still needed, because work does not progress evenly and estimates are rarely exact.

For you: update the remaining time whenever it changes. A started task that nobody updates moves its expected finish one day later every day, and uses buffer as it goes. See Updating a started task.

The buffer sets the priority

LYNX-X compares, for every chain, how much of the chain is complete with how much of its buffer is used. In Portfolio > Project list, the Performance column shows both; with Show all buffers (most critical first) selected at the top right, it shows one gauge per buffer.

From that comparison LYNX-X calculates a CCPM priority for every task of a released project, and orders the work by it.

For you: work your list from the top. You do not set task priorities by hand: LYNX-X puts first the work whose chain is most at risk. See Why one task comes before another.

Related articles

• Updating a started task
• Why one task comes before another
• Working from My activities

Revision history