analysis of cost optimization through crane quantity

Application of Scope, Schedule, Cost Modeling to:

Norbert Chang and Christopher Pickard3/2/2016

O P E N S I T E C O N D I T I O N S

Take Home Messages - Results

Insight 1: Diminishing returns on days reduced for each additional crane past 2 cranes

Insight 2: Level-by-level construction results in shorter schedule duration and reduced subsequent cost

Insight 3: Economic tradeoffs for reduced project duration

Baseline vs Optimized Result Comparison

** bold metrics are in comparison to baseline

Criteria Baseline 1 – Crane 2 – Crane 3 – Crane 4 – Crane

ScheduleDuration

60.15 days(including CIP Topping

& CIP Foundation)

48.42 days-20% duration

vs baseline


vs baseline


vs baseline


vs baseline

Project Cost $8,231,268.39 $8,145,895.15-1.04% cost vs

baseline

$8,236,504.85+.06% cost vs

baseline

$8,321,867.74+1.10% cost vs

baseline

$8,435,893.74+2.49% cost vs

baseline

Cost per Day Reduced

- $(7,278.20)-.088% of total baseline cost

$175.31+.002% of total

baseline cost

$2,383.77+.03% of total baseline cost


Assumptions

Work Environment:• Unlimited site access / laydown space• Optimal weather conditions and site conditionsSchedule Durations:• Same day grout curing• Crane movement transition period negligible• CIP topping slab can begin after 2 level delay• Materials fabricated and delivered on-time Costs:• 1 time mobilization cost per crane and crew• Direct costs/productivities remain constant

Initial StrategiesLevel by Level ConstructionZone division By Level – Vertical Zones (1, 2, 3, 4, 5, 6) Within Level - Horizontal Zones (A, B, C, and D)Construction Sequence 4 Primary Tasks

› Vertical Elements (Columns & Shearwalls)› Horizontal Elements ( Spandrels & Beams)› Deck Elements (Double and Single Tees)› CIP Topping (Full level with 1 level duration delay)

Cranes 1, 2, 3, and 4 Crane scenario

› Constrained by Construction Sequence

Initial Strategies

BASELINE

1 CRANE

2 CRANE

3 CRANE

4 CRANE

60.15 days

53.43 days

33.14 days

36.05 days

32.13 days

6.27 days--------------$85,373.24 Cost Reduction(-$13,616.14 per day)

17.38 days-------------+$90,609.70 Cost Increase($5,213.45 per day)

2.91 days-------------+$85,362.90 Cost Increase($29,334.33 per day)

1.01 days-------------+$114,026 Cost Increase($112,897.03 per day)

Schedule Durations vs Baseline

Cost Estimates

Baseline 1 Crane 2 Crane 3 Crane 4 Crane $8,000,000.00

$8,050,000.00

$8,100,000.00

$8,150,000.00

$8,200,000.00

$8,250,000.00

$8,300,000.00

$8,350,000.00

$8,400,000.00

$8,450,000.00

$8,500,000.00

$8,231,268.39

$8,145,895.15

$8,236,504.85

$8,321,867.74

$8,435,893.74

T o t al P r o j ect Co s t

60.15 days 48.42 days 30.28 days 24.34 days 22.36 days

Baseline 1 Crane 2 Crane 3 Crane 4 Crane $1,400,000.00

$1,450,000.00

$1,500,000.00

$1,550,000.00

$1,600,000.00

$1,650,000.00

$1,700,000.00

$1,750,000.00

$1,800,000.00

$1,850,000.00

$1,900,000.00

$1,646,054.59

$1,565,014.94

$1,658,688.98

$1,740,768.68

$1,850,409.07

I n d ir e ct Co s t Co m p ar is o n

Cost Estimates (cont.)

2 Crane 3 Crane 4 Crane $-

$2,000.00

$4,000.00

$6,000.00

$8,000.00

$10,000.00

$12,000.00

$4,995.02

$7,307.83

$11,128.11

C o s t P e r D a y S a v e d v s

1 - C r a n e

2 Crane 3 Crane 4 Crane

-60.00%

-50.00%

-40.00%

-30.00%

-20.00%

-10.00%

0.00%

10.00%1.11% 2.16% 3.56%

-37%

-50%-54%

C o m p a r i s o n t o 1 - c r a n e

Cost Increase Duration Reduction

Take Home Messages Revisited

Insight 1: Diminishing returns on days reduced for each additional crane past 2 cranes

Insight 2: Level-by-level construction results in shorter schedule duration and reduced subsequent cost

Insight 3: Economic tradeoffs for reduced project duration with additional cranes

1 Crane 2 Crane 3 Crane 4 Crane0%

20%

40%

60%

80%

20%

50%60% 63%

P r o j e c t D u r a t i o n R e d u c t i o n v s B a s e l i n e

Baseline 1 Crane

$8,100,000.00

$8,200,000.00

$8,300,000.00

$8,231,268.39

$8,145,895.15

T o t a l C o s t

Baseline 1 Crane0

20406080 60.15

48.42

T o t a l D u r a t i o n s ( d a y s )

1 Crane 2 Crane 3 Crane 4 Crane

-2.00%

-1.00%

0.00%

1.00%

2.00%

3.00%

-1.04%

0.06%

1.10%

2.49%

T o t a l P r o j e c t C o s t I n c r e a s e v s b a s e l i n e

**Note: 1 crane shows decrease because of sequencing switch from bill-boarding to level by level construction

Open Site Approach Overview RevisitedCriteria Baseline 1 – Crane 2 – Crane 3 – Crane 4 – Crane

ScheduleDuration

60.15 days(including CIP Topping

& CIP Foundation)


vs baseline


vs baseline


vs baseline


vs baseline

Project Cost $8,231,268.39 $8,145,895.15-1.04% cost vs

baseline

$8,236,504.85+.06% cost vs

baseline

$8,321,867.74+1.10% cost vs

baseline

$8,435,893.74+2.49% cost vs

baseline

Cost per Day Reduced

- $(7,278.20)-.088% of total baseline cost

$175.31+.002% of total

baseline cost



** bold metrics are in comparison to baseline

Recommendations for the application of SSC ModelingWhat would do the following again…• Utilize LBS (location based scheduling)• Consistency between scheduling and cost nomenclature /

categorization• Adaptable tools / financial models• Resource load schedule

What we would do the following differently…• Encompass entire process from pre-fabrication to installation• Taken into consideration more detailed crane logistics• Indirect costs could be analyzed in greater detail

Main Personal Lessons LearnedChris• LBS / Pull Production System • 4D modeling / sequencing• CPM/ resource loaded scheduling

Norbert• Quick hand analysis / sequencing in the beginning shortens schedule

creation duration• Earned Value Analysis• Variability Analysis

AppendixWhich of the course concepts did you use?• LBS / Pull Production System • 4D modeling / sequencing• CPM/ resource loaded scheduling

Which of the course concepts do you wish you could have used?• Pull Planning outside workflow• Earned Value Analysis• Variability Analysis

analysis of cost optimization through crane quantity

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