Development of a risk-based strategy implementation of a full pre-financed contractor scheme (CPF) in toll road projects to improve time performance

Figures & data

Figure 1. Typical density function of the PERT-beta distribution. Source: Hajdu and Bokor (2016).

Table 1. Application of PERT analysis in construction projects.

No	References	Author	Object Study
1	Time Optimization Using Cpm, Pert and Pdm Methods In The Social And Department Of Kelautan Building Development Project Gresik District	(Maulana & Kurniawan, 2019)	Social And Department Of Kelautan Building Development Project Gresik District
2	Estimating The Probability Distribution of Construction Project Completion Times Based On Drum-Buffer-Rope Theory	(Liu et al., 2021)	A Hydropower Station, The Main Stream Of The Yellow River, Which Is A Large-Scale Cascade Hydropower Station In China
3	Sensitivity Analysis In PERT Networks: Does Activity Duration Distribution Matter?	(Hajdu & Bokor, 2016)	Highway Construction Projects & Cable-Stayed Bridge Construction Project
4	Schedule Risk Analysis by Different Phases of Construction Project Using CPM-PERT And Monte-Carlo Simulation	(Hendradewa, 2019)	Residential Building Project
5	Forecasting Construction Time for Road Projects and Infrastructure Using the Fuzzy PERT Method	(Nemaa & Aswed, 2021)	The Rehabilitation Of The Road Connecting The Intersection Of The Alghadeer District To The Intersection Of The Al-Mudraa, Karbala City, Iraq
6	Estimation of Task Completion Times with The Use of The PERT Method on The Example of a Real Construction Project	(Plebankiewicz et al., 2015)	Flats Projects In Warsaw, Poland
7	A Fuzzy Pert Approach to Evaluate Plant Construction Project Scheduling Risk Under Uncertain Resources Capacity	(Hsiau & Lin, 2009)	Plant Construction Project In Taiwan
8	Comparison Of PERT And M-PERT Scheduling for A Construction Project in Malang, Indonesia	(Handoko & Gondokusumo, 2019)	Building Construction Projects In Malang
9	Application of Project Evaluation and Review Techniques (PERT) in Project Road Construction in Nigeria	(Kehinde Onifade et al., 2017)	Road Construction In Nigeria
10	Project Evaluation and Review Technique (PERT) Analysis In The Renovation Project Of The Church Of St. John The Evangelist, Jakarta	(Mariana & Wijaksono, 2021)	The Renovation Project Of The Church Of St. John The Evangelist, Jakarta
11	Schedule Modeling To Estimate Typical Construction Durations And Areas Of Risk For 1000 MW Ultra-Critical Coal-Fired Power Plants	(H. C. Lee et al., 2018)	The Construction 1000 MW Gross-Power Ultra-Critical Coal-Fired Power Plants Project In Korea

Table 2. Problem formulation in research strategy.

No	Formulation of the problem	Instrument
1	What are the factors causing delays in toll road construction projects under the Contractor Full Pre-Financed contract scheme?	Literature Study, Questionnaire, Expert Validation
2	What risk indicators are dominant in toll road construction projects with a time performance scheme?	Focus Group Discussion, Qualitative Risk Analysis
3	How big is the impact of the additional time due to the risks that occur in toll road construction projects with the Contractor Full Pre-Financed contract scheme?	Focus Group Discussion, Quantitative Risk Analysis
4	How to formulate the development of a project strategy to anticipate the dominant risks that exist in a toll road construction project with a Contractor Full Pre-Financed scheme so as to improve project time performance?	Focus Group Discussion, Quantitative Risk Analysis

Table 3. Validated risk factor.

Code	Risk factor
R01	Contractor liquidity problems
R02	Losses Due to Interest Rate Fluctuations
R03	Liquidity problems of Sub-Contractors and/or Vendors
R04	Force Majeure
R05	Weather Conditions
R06	Economic Conditions
R07	Land Acquisition Issues
R08	Design error
R09	Design revision delays
R10	Unforeseen difficulties of execution of construction against design
R11	Poor project management team skills
R12	Poor Relationship Management
R13	Poor field management and supervision
R14	Improper intervention
R15	Late payment of sub-contractors
R16	Improper machine work plan
R17	Errors in planning and scheduling
R18	Inappropriate construction methods
R19	Contract Document Disputes
R20	Excessive change requests

Table 4. Critical path of a case study project.

Activity	Duration (day)
Embankment Works on Main Road STA 18 + 600 to 18 + 950	180
Aggregate foundation layer Works on Main Road STA 18 + 600 to 18 + 950	4
Lean Concrete on rigid pavement Main Road STA 18 + 600 to 18 + 950 work	4
Rigid Pavement on Main Road Work STA 18 + 600 to 18 + 950	7
Concrete Median Barrier Work on Main Road STA 18 + 600 to 18 + 950	7

Table 5. Qualitative risk analysis results: dominant risk in critical path activities.

Activity	Duration (day)	Dominant risk
Embankment Works on Main Road STA 18 + 600 to 18 + 950	180	Contractor liquidity problems
Aggregate foundation layer Works on Main Road STA 18 + 600 to 18 + 950	4	Unexpected difficulties
Lean Concrete on rigid pavement Main Road STA 18 + 600 to 18 + 950	4	Sub-Contractor and/or Vendor Liquidity Issues
Rigid Pavement on Main Road STA 18 + 600 to 18 + 950	7	Contractor Liquidity Problems
Concrete Median Barrier Work on Main Road STA 18 + 600 to 18 + 950	7	Sub-Contractor and/or Vendor Liquidity Issues

Table 6. Quantitative analysis inherent risk using with the PERT distribution method.

Activity	Duration (days)	Risk event	Delay (days) – Residual risk			PERT	Theoritical value			Simulation value
			Pessimistic (P)	Most likely (M)	Optimistic (O)		α = 80%	α = 90%	α = 95%	α = 80%	α = 90%	α = 95%
Embanknment Works on Main Roads STA 18 + 600 to 18 + 950	180	Contractor Liquidity Problem	60	45	30	45.000	50.202	52.601	54.322	50.201	52.599	54.322
Aggregate Foundation Layer Work on Main Road STA 18 + 600 to 18 + 950	4	Unexpected Difficulties	14	7	5	7.833	9.2134	10.0642	10.7383	9.2133	10.0638	10.7366
Lean Concrete Work on Main Road STA 18 + 600 to 18 + 950	4	Sub-Contractor and/or Vendor Liquidity Issues	14	7	5	7.833	9.2134	10.0642	10.7383	9.2128	10.0639	10.738
Rigid Pavement Work on Main Road 18 + 600 to 18 + 950	7	Contractor Liquidity Problem	14	7	5	7.833	9.2134	10.0642	10.7383	9.2133	10.0638	10.7383
Concret Median Barrie on Main Road STA 18 + 600 to 18 + 950	7	Sub-Contractor and/or Vendor Liquidity Issues	7	5	3	5.000	5.6936	6.0135	6.243	5.6935	6.0131	6.2425

Source: Author Processed Results, 2022.

Table 7. Number of model iterations and confidence level in several other studies.

	Number of model iterations	Confidence level
Considerations on Project Quantitative Risk Analysis (Purnus & Bodea, 2013)	1.000	82.50% and 84.70%
Monte Carlo Simulation and Modeling of Schedule, Cost and Risks of Dasu Hydropower Project (Mubin et al., 2019)	1.000	80%
Economiciiiriskiiianalysisiiiofiidecentralized renewablei energyiinfrastructuresieiAiiMonte CarloiiiSimulationiiapproachi (Arnold & Yildiz, 2015)i	10.000	–
Fuzzy Monte Carlo Simulation and Risk Assessment in Construction (Sadeghi et al., 2010)	–	60% and 95%
Author research	10.000	80%, 90% and 95%

Table 8. The PERT distribution model in a case study project with inherent risk.

Figure 2. Results of the strategy development FGD in the case study Project-1. Source: Author Processed Results, 2022.

Figure 3. Results of the strategy development FGD in the case study Project-2. Source: Author Processed Results, 2022.

Figure 4. Risk Strategy Model on Main Road STA 18 + 600 to 18 + 950.

Figure 5. Risk Strategy Model on Main Road STA 18 + 600 to 18 + 950.

Figure 6. Risk Strategy Model on Main Road STA 18 + 600 to 18 + 950.

Figure 7. Risk Strategy Model on Main Road STA 18 + 600 to 18 + 950.

Figure 8. Risk Strategy Model on Main Road STA 18 + 600 to 18 + 950.

Table 9. Change of inherent risk value to residual risk value (days delay) after implementing the strategy on the critical path due to dominant risk.

No	Activity (critical path)	Duration (days)	Dominant risk	Delay (days) – inherent			Delay (days) – residual
				P	ML	O	P	ML	O
1	Embankment Works on Main Road STA 18 + 600 to 18 + 950	180	Contractor Liquidity Problems	60	45	30	30	14	7
2	Aggregate Foundation Layer Work on Main Road STA 18 + 600 to 18 + 950	4	Unexpected Difficulties	14	7	5	7	3	2
3	Lean Concrete Work on Main Road STA 18 + 600 to 18 + 950	4	Sub-Contractor and/or Vendor Liquidity Issues	14	7	5	7	3	2
4	Rigid Pavement Work on Main Road STA 18 + 600 to 18 + 950	7	Contractor Liquidity Problems	14	7	5	7	3	2
5	Concrete Median Barrier on Main Road STA 18 + 600 s.d 18 + 950	7	Sub-Contractor and/or Vendor Liquidity Issues	7	5	3	3	2	1

Table 10. Quantitative analysis residual risk using with the PERT distribution method .

Activity	Duration (days)	Risk event	Delay (days) – Residual risk			PERT	Theoritical value			Simulation value
			Pessimistic (P)	Most likely (M)	Optimistic (O)		α = 80%	α = 90%	α = 95%	α = 80%	α = 90%	α = 95%
Embanknment Works on Main Roads STA 18 + 600 to 18 + 950	180	Contractor Liquidity Problem	30	14	7	15.500	19.2418	21.3493	22.9719	19.242	21.348	22.971
Aggregate Foundation Layer Work on Main Road STA 18 + 600 to 18 + 950	4	Unexpected Difficulties	7	3	2	3.500	4.2513	4.7267	5.1064	4.2509	4.7264	5.1059
Lean Concrete Work on Main Road STA 18 + 600 to 18 + 950	4	Sub-Contractor and/or Vendor Liquidity Issues	7	3	2	3.500	4.2513	4.7267	5.1064	4.2511	4.7266	5.1062
Rigid Pavement Work on Main Road 18 + 600 to 18 + 950	7	Contractor Liquidity Problem	7	3	2	3.500	4.2513	4.7267	5.1064	4.251	4.7265	5.1063
Concret Median Barrie on Main Road STA 18 + 600 to 18 + 950	7	Sub-Contractor and/or Vendor Liquidity Issues	3	2	1	2.000	2.3468	2.5067	2.6215	2.3467	2.5067	2.6215

Table 11. The PERT distribution model in a case study project with residual risk.

Table 12. Comparison of time performance based on inherent and residual value schedule model.

Schedule model		Completion time (inherent value)	Completion time (residual value)	Schedule model		Completion time (inherent value)	Completion time (residual value)
Existing Condition	Duration (Day)	214.04		Theoretical Value (Confidence Level 95%)	Duration (Day)	296.08	249.85
	Date of completion	December 23rd, 2022			Date of completion	May 3rd, 2023	February 18th, 2023
PERT Value	Duration (Day)	279.7	238.54	Simulation Value (Confidence Level 80%)	Duration (Day)	288.35	244.13
	Date of completion	April 7th, 2023	January 31st, 2023		Date of completion	April 21st, 2023	February 9th, 2023
Theoretical Value (Confidence Level 80%)	Duration (Day)	288.35	244.13	Simulation Value (Confidence Level 90%)	Duration (Day)	292.77	247.36
	Date of completion	April 21st, 2023	February 9th, 2023		Date of completion	April 28th, 2023	February 14th, 2023
Theoretical Value (Confidence Level 90%)	Duration (Day)	292.77	247.36	Simulation Value (Confidence Level 95%)	Duration (Day)	296.08	249.85
	Date of completion	April 28th, 2023	February 14th, 2023		Date of completion	May 3rf, 2023	February 18th, 2023

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