# Reviewing CPM schedules using Primaveraâ€™s Planner

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```					Reviewing CPM
schedules
using Primavera’s Planner/Scheduler 5.0
(P3ec)

Presented by
Don McNatty
Agenda

Reviewing CPM schedules
A simple process for avoiding headaches…

 What is a CPM schedule?
 Why require it?
 Why get it electronically?
 The Key elements of the CPM submittal
 A process for reviewing schedules with P3ec
 Tools for reviewing schedules
 The importance of perspective
 Questions
Reviewing CPM Schedules

What is a CPM schedule?
Is it too complex?

 Critical Path Method
 The “critical path” is the longest path of activities through a
schedule that determines the schedule completion date.
 A delay to any activity on the “critical path” will impact the
completion date of the schedule.
 A “CPM” schedule can be used to identify “what’s
important” at any point in time
Critical Path Method (CPM)
CPM Calculations
Forward Pass
 Calculates the Earliest Dates
(Start Day + Duration – 1)
1        5

A
5

6
X11                 20
XX25
C
15

1               10

B
10
CPM Calculations
Backward Pass
 Calculates the Latest Dates
(Finish Day - Duration + 1)
1       5

A
5

6       10            11               25
C
15

11               25
1               10

B
10

1                10
CPM Calculations
Total Float
 Is the Difference between the Late and Early Dates

(TF = LF - EF)
1       5

A
5
TF=5
6       10             11                    25
C
15

11         TF=0       25
1                10
Critical Path = B, C
B
10

1       TF=0     10
Negative Float
Late Dates are Earlier than your Early Dates
 Caused by a constraint

1        5

A
5
TF=0
1        5            11                       25
C
15
FNL=20
6          TF=-5         20
1                10
Critical Path = B, C
B
10

-4   TF=-5       5
Calendars convert work days to dates
Reviewing CPM Schedules

Why Require it?
What is the benefit of a CPM schedule?

 Do you want to be able to control your project?
 Do you want an “early warning” of potential
problems?
 Do you want to be able to identify where to focus
your efforts to avoid or solve problems?
 A good CPM tells the project manager what has
to be done, where, when and by who?
Define activities based on
WBS/OBS Matrix
What does a good (useful) project schedule
provide?

What has to be done?
Where does it have to happen?                       4
Who is responsible for doing it?
When does it have to happen?

When a project manager has this information, the
pm has the basis for “control”
Reviewing CPM Schedules

Why Require it electronically?
Do I still need the paper?

 The schedule is a tool. (it may also be evidence).
 Get all evidence in hardcopy first (PDF?)
 Get the electronic version so you can analyze it
 Comparing the electronic versions between each
update can give you a perspective beyond the
hardcopy
Reviewing CPM Schedules

Why Require it electronically?
Do I still need the paper?

 Each monthly update provides a complete audit
trail, should you ever need it.
 Having the electronic copy also let’s you do
“what-if” scenarios.
 You still should get the “hardcopy” just in case
the quality of the electronic copy is poor.
Reviewing CPM Schedules

Schedule submittal specifications are usually Section 01310

 Make it the contractors responsibility to submit the
schedule in a format that can be imported to P3ec 5.0
without variance.
 P3ec imports P3, Suretrak and MS Project files, but
depending on how the scheduler uses them, there can be
conversion issues – make this the contractors problem,
not yours.
 P3ec is a free upgrade to P3 users. Primavera
Contractor costs the same as Suretrak and MS
Project.
Reviewing CPM Schedules

Schedule submittal specifications are usually Section 01310

 Most Important! Insist on a written Narrative that
clearly identifies the presence and reason for:
 Lags, constraints, actuals that have changed since last
update, durations (other than remaining) that have changed
since last update, added and deleted activities,
relationships, codes, descriptions, values…
Reviewing CPM Schedules

Schedule submittal specifications are usually Section 01310

 If you are referencing the contractors schedule to
update your Master schedule, then you should
specify Data Dates in your contract to ensure
alignment of data
 You can import the contractors detailed schedule to P3ec
without importing it to your “master schedule”
 The “master schedule” should be at a summary level
What is the “Data Date”

The remaining schedule starts on
the Data Date…
1   2   3   4   5   6   7   8   9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Data Date (Day 17) is at the first day
of the remaining schedule

Completed Work                                      Remaining Work
Reviewing CPM Schedules

Schedule submittal specifications are usually Section 01310

 If you are referencing the contractors schedule in
your Master schedule, you should specify the
lowest level of your Master Schedule to drive the
highest level of the contractor’s schedule.
 This is a good application for a “schedule of values” so you
can align \$\$\$ with your schedule
Only enough detail for your level of
“control” or “knowledge”

Level 1 - Project
Project 1        Project 2        Project 3
1 Activity per project

Master
Level 2 - Phases
Design          Procure         Construction
Schedule
3-5 Activity’s per project

Level 3 - WorkPackages
Site Prep       Foundation             Slab              Steel
Also called the “CM” schedule. 25 – 35          activities per project.

Level 4 - Contractor
CPM Schedule                 Form Loc 1        Mesh Loc 1          Pour Loc 1

As much detail as needed to communicate W4
Reviewing CPM Schedules

Key elements of CPM submittal?
Remember Jim Zack’s “Scheduling Game # 1” (don’t do it…)

 Letter of Transmittal
 “Hardcopy” Reports – “PDF” is hardcopy…
 Electronic copy of Schedule
 Schedule Narrative
 Schedule Graphic
Reviewing CPM Schedules

Key elements of CPM submittal?
“In a format that can be imported to P3ec 5.0 without variance from
hardcopy…”

 Electronic copy of Schedule
 P3ec (XER) format
 Primavera Contractor 4.1 and higher
 Recommendation: DO NOT convert submittal files, do not
accept Suretrak files that are not in a P3 format. Do not
accept & convert MS Project files – they calculate differently
than P3. Do not accept files that will not open.
Reviewing CPM Schedules

Key elements of CPM submittal?
Insist on a complete narrative or you could be responsible for what you don’t
know that you didn’t know…

 Schedule Narrative
 Baseline (Initial Submittal) should identify and justify all
lags, constraints and hammocks & preferential logic
 Updates should identify all changes from previous submittal
 The Narrative is to the Schedule as the Specifications are
to the Drawings (Drawings are incomplete without specs,
Schedule is incomplete without Narrative…)
Reviewing CPM Schedules

Key elements of CPM submittal?
The schedule may be “evidence”, clearly identify…

 Letter of Transmittal
 Date
 Project
 Data date
 Attachments
Reviewing CPM Schedules

Key elements of CPM submittal?
The electronic schedule file should say the same thing as the hardcopy

 Hardcopy Reports
 Tabular activity list with Early/Late dates, durations, float
 Predecessor/Successor Report (only place you see lags)
 If cost loaded, activities with budgets, this period, to date,
remaining and at completion cost (billing…)
Tabular activity list
Predecessor/Successor Report
Review Narrative
Reviewing CPM Graphics

Key elements of CPM submittal?
Like the tabular report, the bar chart has to say the same thing as the
electronic file

 Schedule Graphic
 A simple bar chart with logic
 Include columns for activity ID, description, early dates,
original and remaining duration, percent complete and total
float
 Highlight progress (Blue) based on Pct, critical path (Red)
based on Longest Path, Baseline (Yellow) under current bar
CPM Bar Chart
Reviewing CPM Schedules

A process for reviewing schedules

 Baselines
 Establish a good starting point and foundation
 Be aware of what changes from update to update
 Time Impact Analysis
 Be aware of the impacts of changes as they happen
BASELINE REVIEW

 Quality Control vs. Audit
 Establish a realistic and useable schedule
 Look at bar chart last
 Recalc & diagnostics
 Check settings & dictionaries
 Evaluate data integrity
 Confirm compliance
 Validate buildability
Baseline Review            Confirm Submittal      Review Baseline Narrative

Recalculate &        Copy and compare, run
Diagnostics         Scheduling-Leveling Report

Schedule Options, User
Check Settings
& Dictionaries        Preferences
Revise & Resubmit

Calendars, Descriptions, Durations,
Evaluate Data        Relationships, Lags, Float, Critical
Integrity          Paths, Cost/Resource allocation

Confirm            Scope, Constraints, Milestones,
Compliance          Notebooks

Work Sequence, Staging, Site
Validate Buildability   Logistics, Constructability

Accepted, Accepted-As-
Acceptance          Noted or Rejected
Recalculate & Diagnostics
 Import without calculating
 Make a copy & recalculate
 Run a ClaimDigger Report
 Any variance with uncalculated schedule
 Means the schedule was changed after calculating and
before making a backup file
 Then run Scheduling-Leveling Report
 Diagnostics
Import without calculating
Make a copy and recalculate
• Use the EPS to isolate contractor
schedule

• Use the File/Import command to
into P3ec

• Making a copy of the schedule is
as easy as Edit/Copy and Paste

• Open the copied project and
recalculate (use F9)

• Use ClaimDigger to check for any
variances

• Any Variances means the project
was modified in some way
after it’s last calculation
Run ClaimDigger Report
Variances with original submittal?
• Any Variances means the project
was modified in some way
after it’s last calculation

• This may cause the electronic data
to vary from the “hardcopy” in
the submittal

• This is usually just an honest
scheduler trying to meet

• But it means that the schedule file
needs to be resubmitted
Scheduling-Leveling Report
• When you schedule the project,
check the box to log statistics
to a file

• First time using P3ec, you have to
edit the filename so it prints

• Store each submittal in a folder
with the submittal name on it
Scheduling-Leveling Report
Look up the activity…

Data date says
May 2nd…

The Constraint is unsatisfied
because no early start can be before
the data date

Start On constraint says
May 1st…
Check Settings & dictionaries
 Schedule Options
 User Preferences
 Calendars
Schedule Options

Leveling not recommended except
for the contractor to use it
Recalculation not recommended
as an analysis tool to determine
because it may change coststhe
Retained logic is
need for “preferential logic”
default. Progress
Override will ignore
logic you previously
accepted
(see next slide)
Calculation Options
User Preferences

P3ec default
may show
time
Calendars

Use the “Collapse All” command
on the View Menu to summarize
the calendar list
Calendars
Calendars

If the calendars are different, for example this
one doesn’t have holidays in it, do you think that
will cause schedule dates to change?
Evaluate data integrity
 Calendar Assignments
 Descriptions
 Durations
 Relationships, Lags
 Float, Critical Path(s)
Confirm Compliance
 Scope of Work
 Constraints
 Milestones
 Notebooks
Validate Buildability
 Work Sequences
 Staging
 Site Logistics
 Constructability
Baseline Review Questions
Can a schedule be reviewed from just the bar chart?
Why do we recalculate the schedule?
Why are different Calendars utilized?
Why use a standard approach to Descriptions?
Why should we check Lags?
Why should we document Constraints?
Why do we need “hardcopy” along with electronic?
What can the resource histogram tell me?
Reviewing CPM Schedules

A process for reviewing schedules

 A few simple steps and comparisons
 You don’t have to be a scheduler to identify what
has changed, see if it is addressed in the
Narrative, and decide if you agree with why it
changed
Update Review         Confirm Submittal    Review Update Narrative

Recalculate &                        Baseline Comparisons,
Perform Comparison   ClaimDigger Report
Diagnostics

Actual Dates, Percent
Check Settings        Validate
Complete, Rem Durations
& Dictionaries        Progress        Out-Of-Sequence Progress

Evaluate Data        Analyze         Start/Finish Dates,
Integrity         Variances        Changes in Durations

Actual vs. Original Durations,
Confirm            Identify
Current vs. Baseline or
Compliance           Trends         Previous update Float

Validate           Measure         Current vs. Planned Pct Compl,
Buildability      Performance       Earned Value (Res/Cost)

Accepted, Accepted-As-
Acceptance
Noted or Rejected
Track Key Statistics

BASELINE      FIRST       SECOND        THIRD       FOURTH
CATEGORY            SCHEDULE     UPDATE       UPDATE       UPDATE       UPDATE

Total No. of
Activities                 321          325          316          332          336

% Critical Activities
32%          44%          42%          38%            --

Critical Path Total
Float                       0           -10           -8           -4           --

Total % Complete
0%          20%          45%          80%          100%

Project Completion
Date                     3/01/02      3/15/02      3/13/02      3/07/02      3/06/02

Total Resource Qty
At Compl                11,560 hrs   11,640 hrs   11,720 hrs   11,740 hrs   11,710 hrs

Total Costs At
Completion              \$1,250,000   \$1,350,000   \$1,400,000   \$1,450,000   \$1,375,000
Update Review Questions
What two files should we set as Targets so we can
display/compare dates?
How do you compare a schedule if you don’t have one
of the utilities?
Why isn’t it a good idea to change Actv ID numbers?
Can the Critical Path change?
Why do we analyze trends?
In a resc/cost loaded schedule, what would be a good
way to measure performance?
Examples of use on a single project
 Presented by Craig Olsen at a recent UG meeting
 Craig is VP in Construction Services Group at
URS and a Certified Primavera Trainer
 Imported schedules from multiple sources
 P3, Suretrak, Excel
 Maintained a summary master schedule for the
overall project
 Referenced contractors schedules for updating master
 Example show how to focus on one specific
group of activities – concrete pours
Projects Screen
Summary By P3 File
Summary By File & Area
Summary By Area & File
Summary of Pours
Detail of selected Pours
Detail by Activity by File
Reviewing CPM Schedules

The importance of “perspective”
Does the schedule reflect how the work is being done?

 The higher the percentage of “out of sequence”
work the less the schedule is being followed
 If changes don’t make sense, can’t or aren’t
explained…, the schedule is going out of control
 The Narrative is probably more important than
the schedule – it’s in english…
Schedule Review Course
 Full course covers two days
 Includes review of CPM fundamentals
 Detailed, hands on use of P3ec for
 Baseline review
 Update review
 Time Impact Analysis
 DRMcNatty is a Certified Primavera Trainer and
Authorized Representative
 Have focused on implementing Primavera tools for almost
20 years
Questions?

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