T.L. Martin & Associates Copyright © 2008 Chapter 1 Fundamentals of Scheduling T.L. Martin &...

T.L. Martin & AssociatesT.L. Martin & Associates

Copyright © 2008Copyright © 2008

Chapter 1Chapter 1Fundamentals of SchedulingFundamentals of Scheduling

T.L. Martin & Associates, Inc.18552 Office Park Drive

Gaithersburg, Maryland 20886Phone (240) 632-1710 & FAX (240) 632-1712

e-mail: [email protected]



The FundamentalsThe Fundamentals

• The primary goal of a schedule is to manage time.

• A plan is an order of work.

• When time frames are applied to a plan, a schedule is created.

• Critical Path Method is used to forecast when work activities are to take place.



When to Use a CPMWhen to Use a CPM

• A CPM is used when the scope of work of a project becomes complex.

• A bar chart can not capture the many relationships between activities in a complex project.

• Rule of thumb - any project with over forty (40) definable tasks.



Why Use a CPM ScheduleWhy Use a CPM Schedule

• Contractor is responsible for planning, scheduling and progressing the work.

• An Owner and its representatives must assure that the contractor meets its obligations.



Why Use a CPM ScheduleWhy Use a CPM Schedule

• If a contractor fails:– Then an Owner may withhold progress

payments – or default terminate the contractor.

• The schedule is vital.



Bar Chart SchedulesBar Chart Schedules

• The bar chart is an excellent tool.

• Work tasks or activities are shown as bars across a horizontal calendar.

• If a bar chart is prepared carefully, the planner logically times the work based on:– physical restraints– contractual restraints– realistic use of men and equipment.



Bar Chart ScheduleBar Chart ScheduleFoundation Project Bar Chart

Description 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Excavate

Form Ftg & Slab

Place Rebar

Install MEP Rough-In

Inspect & Pour

Review FND Design

Special PM

Scheduled Periods

Bars Indicate When in Time a Work Task is Planned to be Performed.



Bar Chart ScheduleBar Chart Schedule

• A bar chart can include budgets versus actual. • Tasks or activities are resource loaded across

the horizontal calendar.• This allows a real-time view of budget versus

actual highlighting any problems of selected important project components such as: – manpower - costs– equipment - revenue– cash flow - material– activity timing (ahead or behind plan)




Description Quantity UMMan-Hours

$ x $1,000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Excavate 250 cyMan-Hours 270 90 90 90

Cost $4.2Form Ftg & Slab 1,600 csf

Man-Hours 180 60 60 60Cost $3.6

Place Rebar 5 tonMan-Hours 60 20 20 20

Cost $3.3Install MEP Rough-In 1 ls

Man-Hours 120 40 40 40Cost $6.0

Inspect & Pour 100 cyMan-Hours 90 30 30 30

Cost $2.7Review FND Design 1 ls

Man-Hours 10 5 5Cost $0.8

Special PM 1 lsMan-Hours 48 8 8 8 8 8 8

Cost $3.0

Man-Hours 778 90 95 95 68 68 68 28 28 28 40 40 40 30 30 30$ x 1,000 $23.6Man-Hours 90 185 280 348 416 484 512 540 568 608 648 688 718 748 778$ x 1,000

Man-Hours 78 117 150 234 312$ x 1,000

Scheduled Periods

Daily Total

Cumulative Total

Actual To Date

Add Planned Resources, Spread to Time Periods of Performance, Sum Total of All Tasks for Each Period.





$ x $1,000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15Tot

Total Man-Hours

Excavate 250 cy 780Man-Hours 270 90 90 90 741

Cost $4.2 702Form Ftg & Slab 1,600 csf 663

Man-Hours 180 60 60 60 624Cost $3.6 585

Place Rebar 5 ton 546Man-Hours 60 20 20 20 507

Cost $3.3 468Install MEP Rough-In 1 ls 429

Man-Hours 120 40 40 40 390Cost $6.0 351

Inspect & Pour 100 cy 312Man-Hours 90 30 30 30 273

Cost $2.7 234Review FND Design 1 ls 195

Man-Hours 10 5 5 156Cost $0.8 117

Special PM 1 ls 78Man-Hours 48 8 8 8 8 8 8 39

Cost $3.0 0

Man-Hours 778 90 95 95 68 68 68 28 28 28 40 40 40 30 30 30$ x 1,000 $23.6Man-Hours 90 185 280 348 416 484 512 540 568 608 648 688 718 748 778$ x 1,000

Man-Hours 78 117 150 234 312$ x 1,000

Scheduled Periods

Daily Total

Cumulative Total

Actual To Date

Man-Hours

Planned versus Actual Can be Compared.





$ x $1,000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15Total Cost X $1,000

Excavate 250 cy $28.0Man-Hours 270 90 90 90 $26.6

Cost $4.2 1.4 1.4 1.4 $25.2Form Ftg & Slab 1,600 csf $23.8

Man-Hours 180 60 60 60 $22.4Cost $3.6 1.2 1.2 1.2 $21.0

Place Rebar 5 ton $19.6Man-Hours 60 20 20 20 $18.2

Dollars $3.3 1.1 1.1 1.1 $16.8Install MEP Rough-In 1 ls $15.4

Man-Hours 120 40 40 40 $14.0Cost $6.0 2 2 2 $12.6

Inspect & Pour 100 cy $11.2Man-Hours 90 30 30 30 $9.8

Cost $2.7 0.9 0.9 0.9 $8.4Review FND Design 1 ls $7.0

Man-Hours 10 5 5 $5.6Cost $0.8 0.4 0.4 $4.2

Special PM 1 ls $2.8Man-Hours 48 8 8 8 8 8 8 $1.4

Cost $3.0 0.5 0.5 0.5 0.5 0.5 0.5 $0.0

Man-Hours 778 90 95 95 68 68 68 28 28 28 40 40 40 30 30 30Dollars x 1,000 $23.6 1.4 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 2 2 2 0.9 0.9 0.9Man-Hours 90 185 280 348 416 484 512 540 568 608 648 688 718 748 778$ x 1,000 1.4 3.2 5.0 6.7 8.4 10.1 11.7 13.3 14.9 16.9 18.9 20.9 21.8 22.7 23.6

Man-Hours 78 117 150 234 312$ x 1,000 1 1.4 2.8 4.2 5.6

Scheduled Periods

Daily Total

Cumulative Total

Actual To Date

Cost

Planned versus Actual Costs Can be Compared.





$ x $1,000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15Total Cost X $1,000

Total Man-Hours

Excavate 250 cy $28.0 780Man-Hours 270 90 90 90 $26.6 741

Cost $4.2 1.4 1.4 1.4 $25.2 702Form Ftg & Slab 1,600 csf $23.8 663

Man-Hours 180 60 60 60 $22.4 624Cost $3.6 1.2 1.2 1.2 $21.0 585

Place Rebar 5 ton $19.6 546Man-Hours 60 20 20 20 $18.2 507

Cost $3.3 1.1 1.1 1.1 $16.8 468Install MEP Rough-In 1 ls $15.4 429

Man-Hours 120 40 40 40 $14.0 390Cost $6.0 2 2 2 $12.6 351

Inspect & Pour 100 cy $11.2 312Man-Hours 90 30 30 30 $9.8 273

Cost $2.7 0.9 0.9 0.9 $8.4 234Review FND Design 1 ls $7.0 195

Man-Hours 10 5 5 $5.6 156Cost $0.8 0.4 0.4 $4.2 117

Special PM 1 ls $2.8 78Man-Hours 48 8 8 8 8 8 8 $1.4 39

Cost $3.0 0.5 0.5 0.5 0.5 0.5 0.5 $0.0 0

Man-Hours 778 90 95 95 68 68 68 28 28 28 40 40 40 30 30 30$ x 1,000 $23.6 1.4 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 2 2 2 0.9 0.9 0.9Man-Hours 90 185 280 348 416 484 512 540 568 608 648 688 718 748 778$ x 1,000 1.4 3.2 5.0 6.7 8.4 10.1 11.7 13.3 14.9 16.9 18.9 20.9 21.8 22.7 23.6

Man-Hours 78 117 150 234 312$ x 1,000 1 1.4 2.8 4.2 5.6

Scheduled Periods

Daily Total

Cumulative Total

Actual To Date

Man-Hours

Cost



Bar Chart ScheduleBar Chart Schedule

• A bar chart can include important budgets versus actual recorded for each Task.

• The Bar Chart May become Crowded. It is important to Select the Most Meaningful project components to Monitor.

• The following Bar Chart is an Example which Monitors:– Man-Hours - Costs - Revenue

T.L. Martin & Associates Copyright © 2008T.L. Martin & Associates Copyright © 2008

Foundation Project Bar Chart


$ x 1,000 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15900 MH

Excavate 250 cyActual To Date 300 cyMan-Hours 270 90 90 90

Actual To Date 178 89 89 800 MHCost $4.20 $1.40 $1.40 $1.40

Actual To Date $3.00 $1.50 $1.50Revenue $5.29 $1.76 $1.76 $1.76

Actual To Date $5.29 $2.65 $2.65

Form Ftg & Slab 1,600 csf

Actual To Date 1,000 csf 700 MHMan-Hours 180 60 60 60

Actual To Date 125 25 50 50Cost $3.60 $1.20 $1.20 $1.20

Actual To Date $2.50 $0.50 $1.00 $1.00Revenue $4.54 $1.51 $1.51 $1.51

Actual To Date $2.84 $0.57 $1.13 $1.13 600 MH

Place Rebar 5 ton

Actual To Date

Man-Hours 60 20 20 20Actual To Date

Cost $3.30 $1.10 $1.10 $1.10Actual To Date 500 MH

Revenue $4.16 $1.39 $1.39 $1.39Actual To Date

Install MEP Rough-In 1 ls

Actual To Date

Man-Hours 120 40 40 40Actual To Date 400 MH

Cost $6.00 $2.00 $2.00 $2.00Actual To Date


Inspect & Pour 100 cy

Actual To Date 300 MHMan-Hours 90 30 30 30

Actual To Date

Cost $2.70 $0.90 $0.90 $0.90Actual To Date


Review FND Design 1 ls 200 MH

Actual To Date 100% %Man-Hours 10 5 5

Actual To Date 8 4 4Cost $0.80 $0.40 $0.40

Actual To Date $0.64 $0.32 $0.32Revenue $1.01 $0.50 $0.50 100 MH

Actual To Date $1.01 $0.50 $0.50

Project Management 15 Periods

Actual To Date 5 PeriodsMan-Hours 120 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8

Actual To Date 40 8 8 8 8 8Cost $9.00 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 $0.60 0 MH

Actual To Date $2.55 $0.51 $0.51 $0.51 $0.51 $0.51Revenue $11.34 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76 $0.76

Actual To Date $3.78 $0.76 $0.76 $0.76 $0.76 $0.76

Man-Hours 98 201 304 372 440 508 536 564 592 640 688 736 774 812 850Cost $ x 1,000 $2.00 $4.40 $6.80 $8.60 $10.40 $12.20 $13.90 $15.60 $17.30 $19.90 $22.50 $25.10 $26.60 $28.10 $29.60Revenue $ x 1,000 $2.52 $5.54 $8.57 $10.84 $13.10 $15.37 $17.51 $19.66 $21.80 $25.07 $28.35 $31.63 $33.52 $35.41 $37.30

Man-Hours 97 198 235 293 351 Cost $ x 1,000 $2.01 $4.34 $5.67 $7.18 $8.69 Revenue $ x 1,000 $3.40 $7.31 $9.14 $11.03 $12.92

Scheduled Periods

Planned Cumulative Total

Actual Cumulative Total

Da

ta D

ate

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5

$0.00

$5.00

$10.00

$15.00

$20.00

$25.00

$30.00

$35.00

$40.00

$ x

1,00

0

Planned Cumulative Total Man-Hours

Actual Cumulative Total Man-Hours

Planned Cumulative Total Cost $ x 1,000

Planned Cumulative Total Revenue $ x 1,000

Actual Cumulative Total Cost $ x 1,000

Actual Cumulative Total Revenue $ x 1,000

Budget Revenue is Close to Actual Revenue, Thus Project is on Time

Both Man-Hours and Costs are Less than Budgeted, Thus Project so Far is a Winner.

Note Actual Timing, Man-Hours, Cost and Earned Revenue are Recorded and Compared with Budgets.



Bar Chart SchedulesBar Chart Schedules

• Bar chart does not include logic lines.

• More complex Projects require interrelated activities.

• A simple bar chart cannot capture the many relationships and interdependencies between activities on complex projects.



The CPM ScheduleThe CPM Schedule

• CPM requires the detailed planning and scheduling of all elements of a project, from start to completion.

• CPM results in a network of tasks of:– Defined duration,– Tied together by physical, contractual and

selected optional relationships.



Critical Path Method ScheduleCritical Path Method Schedule

5

5

5

5

52

S S S S S S S SM T W T F M T W T F M T W T F M T W T F

Excavate

Place Rebar

Install MEPRough In

10

InspectFND

Review/Approve FNDDesign

Inspect andPour

Form Footing& Slab

The standard Finish-Start relationship. An Activity Finishes so Following Activity can Start.



The CPM ScheduleThe CPM Schedule• Once a network of activities has been

created, task start and finish dates can be computed.

• The longest activity chain, from the start of the project to its completion, is termed the projects Critical Path.



The CPM ScheduleThe CPM Schedule

• An activity or task is:– definable– must be accomplished

• The activity includes:– duration– linked to other activities



The CPM ScheduleThe CPM Schedule• Budget Resources, Costs and Revenue

may be assigned to each Network activity.

• After the CPM is created it can be updated with current project information. – Actual Timing: Start, % Complete, Finish– Resources Used

• Man-Hours ● Equipment-Hours • Material Quantities ● Costs • Other Components

• Monitor Budgets versus Actual Timely.



The CPM Schedule - RelationshipsThe CPM Schedule - Relationships

• Physical dependence and requirements between activities generally can not be changed. – One work element builds on a previous one. – Site constraints – Special weather considerations



• Contractual requirements:– Owner imposed phasing of the work. – Permitting issues, – Owner furnished equipment,– Land procurement, – Early turnover of certain areas of the project.





• Physical and contractual requirements are rigid.

• Activity relationships based on contractor options are far more flexible. – Manpower– Equipment – Contractor’s approach to the project, the

contractor’s “means and methods.”



Please Proceed to Please Proceed to Chapter 2 Chapter 2 Key CPM Scheduling TermsKey CPM Scheduling Terms

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