Optimizing Costs and Time in the Cintapuri Road Project: Two Hours of Overtime Emerges as the Most Efficient Option

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FORMOSA NEWS

Adding two hours of overtime work per day is the most efficient strategy for accelerating the Cintapuri Banua Hanyar Road and Bridge Reconstruction Project in Banjar Regency, South Kalimantan. This finding comes from a study conducted by Kanniya Muthia Fatmawati, H. Muhammad Humaidi, and Hendri Yani Saputra from Politeknik Negeri Banjarmasin, published in 2026 in the International Journal of Integrative Research (IJIR). The research demonstrates that project schedules can be shortened significantly while maintaining cost efficiency through a Time-Cost Trade-Off (TCTO) analysis supported by Microsoft Project 2021.

Time and cost management are among the most critical factors in the success of construction projects. When a project must be completed faster than originally planned, contractors often increase resources or extend working hours. However, faster completion usually leads to higher costs. Therefore, project managers need reliable methods to identify acceleration strategies that deliver the greatest time savings with the lowest possible cost increase.

The study focused on the Cintapuri Banua Hanyar–Galam Rabah Road and Bridge Reconstruction Project located in Cintapuri Darussalam District, Banjar Regency, South Kalimantan. The project, managed by the Banjar Regency Public Works and Spatial Planning Office (PUPRP), had a contract value of IDR 6.6 billion and an initial completion target of 150 calendar days.

To evaluate optimization opportunities, the researchers analyzed project planning documents, including the Cost Budget Plan (RAB), project schedule, and Unit Price Analysis (AHSP). These data were modeled using Microsoft Project 2021 to establish the project network and identify activities on the critical path. Critical path activities are tasks that directly determine the overall project duration, meaning any delay in these activities will delay the entire project.

The analysis identified ten critical activities, including mobilization, temporary bridge construction, traffic management and safety, ordinary excavation, selected embankment work, Class 1 geotextile separator installation, Class A aggregate base layer, Class B aggregate base layer, tack coat application, and Hot Rolled Sheet Base (HRS-Base) pavement work.

After identifying the critical path, the researchers simulated project acceleration by adding one, two, and three hours of overtime work per day to critical activities. Each scenario was evaluated based on its impact on project duration, acceleration costs, and the ratio between additional costs and time savings.

The results revealed that longer overtime periods consistently reduced project duration. However, increased overtime also raised overall project costs because of additional labor wages and equipment operating expenses.

The findings showed:

• 1 hour of overtime per day reduced the project duration to 140.44 days, saving 9.56 days.
• 2 hours of overtime per day reduced the project duration to 134.36 days, saving 15.64 days.
• 3 hours of overtime per day reduced the project duration to 132.75 days, saving 17.25 days.

Although the three-hour overtime scenario achieved the shortest completion time, it was not the most economical solution. The additional costs required to gain the final days of acceleration were disproportionately high.

Using the Cost-Time Ratio indicator, the researchers found that the two-hour overtime scenario delivered the best balance between cost and schedule reduction. This option produced the lowest Cost-Time Ratio at IDR 225,040,629.90 per day of acceleration, outperforming the one-hour overtime scenario at IDR 309,152,660.65 per day and the three-hour overtime scenario at IDR 236,780,979.18 per day.

According to the researchers, the efficiency of the two-hour overtime scenario is linked to worker productivity levels. Productivity remains relatively high during the first two overtime hours, but begins to decline significantly when overtime extends to three hours. Worker fatigue reduces effectiveness, making the third overtime hour less productive and more expensive.

The study found that extending overtime from two to three hours only generated an additional acceleration of approximately 1.61 days, yet required more than IDR 564 million in extra costs. As a result, the three-hour overtime option was considered financially inefficient despite delivering the shortest project duration.

These findings provide valuable insights for construction companies and infrastructure project managers. Accelerating a project does not necessarily mean maximizing overtime hours. Instead, decision-makers should focus on finding the optimal balance between productivity gains and cost increases.

H. Muhammad Humaidi and his colleagues emphasized that the Time-Cost Trade-Off approach can help contractors and project owners make more informed decisions when facing tight deadlines. By utilizing Microsoft Project, various acceleration scenarios can be simulated and evaluated before implementation in the field.

The study also offers practical implications for government agencies responsible for public infrastructure projects. Data-driven acceleration strategies can help minimize budget overruns while ensuring projects are completed on schedule.

The researchers recommend future studies that combine overtime strategies with additional heavy equipment or shift-based work systems to further improve efficiency. They also stress the importance of considering worker fatigue when implementing overtime policies to maintain productivity and workplace safety.

Author Profile

Kanniya Muthia Fatmawati is a researcher in construction management from Politeknik Negeri Banjarmasin.

H. Muhammad Humaidi is a lecturer and researcher at Politeknik Negeri Banjarmasin specializing in construction project management and civil engineering. He served as the corresponding author of this study.

Hendri Yani Saputra is an academic and researcher from Politeknik Negeri Banjarmasin whose expertise includes project management, cost analysis, and infrastructure planning.

Research Source

Fatmawati, K.M., Humaidi, H.M., & Saputra, H.Y. (2026). “Optimization of Total Project Cost for the Cintapuri Banua Hanyar Road and Bridge Reconstruction Project Using Microsoft Project Through Time-Cost Trade-Off Analysis.” International Journal of Integrative Research (IJIR), Vol. 4, No. 7, pp. 593–602. DOI: 10.59890/ijir.v4i7.228.