PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Aka
Float and the Cheshire Cat
The smile is there but the cat is gone
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
The 1st thing you need to decide is
whether Earl IS crazy
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
If YES
and you do not want to psychoanalyze me
then your time would be spent elsewhere
and you are excused.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
If Earl is NOT crazy
Let’s examine these crazy statements
that he is making about Float
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Float – A BANKRUPT BELIEF
Activity Float is a MYTH !
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
The original paradigm of a Critical Path
and the ‘floating’ of activities is no longer a valid concept !
Why Not ???
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
H I S TO R I CAL B E G I N N I N G
The limited ‘special case’ of the first project
scheduled by the Critical Path method
is no longer the real world of scheduling.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
The Kelley-Walker development which used
activities chained into sequences
only used activity durations and
their logical relationships or sequences
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
With only a base calendar and no date
constraints the analysis was free flowing
and open ended
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Hence, the chain of activities which
determined the total time needed to
complete all of the work was the answer to
the problem they were solving.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
AKA the Critical Chain [Dupont]
or
Critical Path [DOD]
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Those paths which were not said to
be determining the project’s end time
had more time to accomplish their work
without affecting the total time were
said to have slack or float time.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
13
The Evolution and Demise of Activity FLOAT
E V O L U T I O N
From 1960 to 1975 many additional
attributes were added to the network
analysis system:
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
– Multiple Calendars– Time/date constraints– Multiple resources– Resource Allocation scheduling– Durations [lead/lag] on
dependencies– Multiple projects
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
T H E E F F E C T ?
Activity performance time was now
segmented according to the availability of
resources, work calendars,
andimposed time/date constraints.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
T H E R E S U L T ?
A continuous time path does not exist !
Therefore, the computation of Activityor Total Path Float while
mathematically possible is not realistic and the utility
of FLOAT becomes misleading.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
The actual path[s] become invisible.
Like the Cheshire cat,
the smile is there but the cat is gone
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
18
The Evolution and Demise of Activity FLOAT
Instead of a ‘Critical Path’there is now a
Critical Sequence
and is the ‘longest path’which may or may not be continuous
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
But, why do we need to know It ?
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
We don’t
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Once the work plan and schedule
are accepted as the ‘plan’
our attention should be on executing the
work according to the plan
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Plan the Work
then
Work the Plan
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Once the plan for doing the work is set
IT CAN NOT BE CHANGED !!
Why not ??
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
The work plan of dates for the start and
completion of all activities and milestones
have been developed based on many
variables.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
The network of activities is actually a very
large number
of simultaneous equations of activities with
time,resources, and calendar variables.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Change just one variable
and
the analysis becomes invalid.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Whoa, wait a minute
We enter actual dates as work is performed
Doesn’t this invalidate the remaining
schedule ?
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
N O
Why not ??
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Because we are working the Plan
Not re-planning the work !
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Once activity actual finish dates are entered
those activities are no longer used in the network analysis
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Is all well ?
NO ?
Why not ?
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
The network analysis will compute
new dates without rescheduling the
resources.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Is this OK ?
NO !
Why not ?
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
The Plan included the activities of many
diverse performers such as sub-contractors,
suppliers, external agencies,
and interfaces with other projects
especially as to their resources
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
And these participants have
other projects they are working on.
Hence, the plan must be fixed and
performance managed to follow that plan
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
C O N C L U S I O N S
Activity Float and Total Float have become
irrelevant and misleading to those
executing the Project work.
To focus on it is a pitfall and booby trap.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
R E C O M M E N D A T I O N
Once the work has been planned and
scheduled ,
status reports resulting from the input of
actual performance and progress should
have the Total Float values suppressed.
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
COMMENTS FROM REVIEWERS
I agree completely with Earl. “Float” is a term planning ‘types’ like to use but working people just want to know when can I start? And when do I have to finish?
-- Robert Youker
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
COMMENTS FROM REVIEWERS
You are right on the money.
-- Abhi Basu, Basutech
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
COMMENTS FROM REVIEWERS
I love the way Earl is able to stir us up to do what I think PMICOS should be about –
the recognition of the manner in which practice is often in conflict with theory and an effort to explore that conflict for the good of the profession
-- Gordon Davis
PMI College of Scheduling“PMI” is a registered trade and service mark of the Project Management Institute, Inc.
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The Evolution and Demise of Activity FLOAT
Earl Glenwright, SME, PSPA.S.S.I.S.T.
P O Box 3305Eagle, Colorado 81631
1-970-328-3131Earl_BG@ yahoo.com
Assist_BG @yahoo.comSofia/Bansko, Bulgaria