May 25, 2026
Application of the Critical Path Method in Schedule Management in Public Works
Victor Hugo Meireles Bressolini; Lorena Hernández Mastrapa
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This research proposed and validated a procedure for planning and controlling schedules in municipal public works in Piumhi, Minas Gerais, aiming to reduce delays and increase efficiency. The approach applied the Critical Path Method (CPM) to analyze the schedule of a real work, comparing the official plan with an optimized one. The investigation sought to demonstrate how identifying critical activities, managing float, and allocating resources can improve time predictability and control, offering a roadmap for public managers to overcome delays and stoppages. The study focused on a practical case to extract applicable lessons and quantify the benefits of formal planning methodologies.
Civil construction is a pillar for socioeconomic development, generating jobs and income (Thielman and Queiroz, 2021). In the public sector, infrastructure projects such as leisure spaces, sanitation, and paving directly impact quality of life and regional development (Filho, 2025). Public administration, governed by the principles of legality and efficiency, must execute these works with quality, cost control, and adherence to deadlines, which represent the delivery of benefits to society (Dangelo et al., 2023). Effective time management is, therefore, an indicator of governmental competence.
Despite its importance, public works management in Brazil faces a high rate of stalled projects. Data from the Federal Court of Accounts (TCU) indicate that, in 2022, 38.5% of federal works were stalled, and in 2024 there were still 11.9 thousand interrupted contracts, with a billion-dollar budgetary impact (Brazil, 2024; G1, 2024). Delays are a chronic problem, with causes including ineffective management, communication failures, labor shortages, and slow decision-making (Maia and Oliveira, 2018). Such failures result in wasted resources and deprive the population of essential infrastructure, requiring a more methodical approach to planning and control (Alves and Silva, 2022).
Project management offers practices and techniques to plan, execute, and control works, ensuring completion within deadline, budget, and quality (Dey, 2018). Schedule management is vital, involving activity definition, duration estimation, resource allocation, and constraint identification (PMI, 2017). A well-developed schedule functions as a strategic tool for coordination and decision-making (Kerzner, 2017), and its absence increases the risk of deviations, making methodologies like CPM a necessity for public management.
The central research question was: how to improve the planning and control of schedules in public works in Piumhi (MG) to reduce delays and increase efficiency? The justification lies in the premise that the lack of time management methodologies is a primary cause for the failure of public projects. By applying the Critical Path Method to a municipal case, the research sought to diagnose failures and propose a path to improve management, offering greater predictability and ensuring that public investments translate into social benefits. The structured approach aims to mitigate risks and strengthen the public sector’s delivery capacity (Lock, 2021).
The research adopted the case study methodology to investigate the application of the Critical Path Method (CPM) in the schedule management of the construction of a public square in the Estrela Branca Lotting, in Piumhi, Minas Gerais (Gil, 2002). This approach allowed for an in-depth and contextualized analysis, with empirical data collection to evaluate planning effectiveness and identify municipal-level challenges (Lozada and Nunes, 2018).
The empirical basis was built from documentary sources of the Prefecture of Piumhi/MG, including the tender notice, basic project, budget spreadsheet, and the original physical-financial schedule. These documents provided information on scope, activities, costs, durations, and the planned execution sequence, ensuring the research’s fidelity and allowing a direct comparison between the original planning and the optimized model.
The data analysis followed the principles of the PMBOK® Guide for Schedule Management (PMI, 2017), divided into six stages. First, activities were defined with the creation of a Work Breakdown Structure (WBS). Second, durations were estimated based on unit cost compositions. Third, activities were sequenced using the precedence diagramming method (PDM). In the fourth stage, the schedule was developed using CPM to calculate dates, float, and the critical path, with the aid of spreadsheets to create the Gantt chart. The fifth stage, schedule control, proposed metrics for comparative analysis between the official and optimized schedule. Finally, the sixth stage performed four simulations of delays in critical and non-critical activities to assess the schedule’s resilience and the impacts of deviations on the final deadline.
The analysis started from the official City Hall schedule, with a deadline of 129 working days (January 5 to July 10, 2026). The first step was to create a detailed Work Breakdown Structure (WBS), breaking down the scope into manageable packages such as “Preliminary Services”, “Infrastructure”, “Lighting”, “Furniture”, and “Final Delivery”. Within these, all activities were listed, from site mobilization to final demobilization, providing a complete view of the work.
Next, the duration and resources for each activity were estimated, using the unit price compositions from the bid. For example, the “Execution of the sidewalk with machined concrete” was estimated at 22 days with a team of four helpers, two masons, and three carpenters. The “Installation of galvanized posts” was planned for 6 days with two helpers and two electricians. This step quantified the effort and established a limit of available resources, such as 10 helpers and 5 masons, to simulate a real scenario.
The initial Gantt chart schedule revealed a resource overallocation problem. The analysis showed that, during certain periods, labor demand exceeded maximum capacity, requiring 15 helpers and 6 masons simultaneously, while the limits were 10 and 5. This inconsistency, if not corrected, would lead to delays, as the team would be insufficient to perform the scheduled tasks.
To resolve the conflict, a resource leveling was performed, reallocating activities to respect labor limits. Four adjustments were implemented: (1) trench excavation was postponed until after the sidewalk execution; (2) the installation of inspection boxes was rescheduled for after the excavation; (3) the power entry was moved to after the installation of the poles; and (4) the installation of the trash bins was sequenced for after that of the benches. These changes optimized the workflow and eliminated demand peaks.
Resource leveling resulted in an optimized schedule that not only resolved the over-allocation but reduced the total project duration. The delivery date was brought forward from July 10, 2026, to May 19, 2026, a reduction of 51 days. Comparative milestone analysis showed that while the “Infrastructure” milestone was delayed by one day, “Lighting” and “Furniture” were brought forward. The result demonstrated that careful planning with tools like CPM generates efficiency gains.
To test the robustness of the schedule, four delay simulations were performed. In Scenario 1, a 6-day delay in the critical activity “Manual excavation of trenches” propagated directly, postponing the project completion by 6 days. In Scenario 2, a 7-day delay in the critical activity “Cutting, spreading, filling, and compaction of soil” extended the final deadline by 7 days. Both scenarios confirmed the project’s sensitivity to deviations in the critical path, underscoring the need for rigorous monitoring of these tasks.
The following scenarios explored non-critical activities. In Scenario 3, a delay in the “Curb settlement” activity was absorbed by its float, with no impact on the delivery date, illustrating the flexibility that floats offer for managing unforeseen events. Scenario 4 simulated a delay in the “Execution of concrete blocks for pole bases” activity that exceeded its float. As a result, the activity became critical, and the project suffered a 10-day delay. This scenario demonstrated that the critical path is not static and that excessive delays in activities with float can alter project priorities. The findings corroborate research by Martins (2022) and Menegazzo and Maceta (2025), who also highlighted CPM for identifying bottlenecks and optimizing resources in construction projects.
The analysis of the square’s design in Piumhi/MG demonstrated that the application of the Critical Path Method contributes to public works management. The tool allowed for the identification of the critical path, diagnosis of failures such as resource overallocation, and optimization of the schedule, resulting in a reduction of 51 days in the delivery deadline. Simulations reinforced the importance of continuous monitoring of critical activities and slack management. The study’s limitations included the absence of specialized software, requiring manual control of the critical path, and the difficulty in obtaining specific productivity data for municipal works. For future work, it is suggested to apply the method to more complex projects, use advanced software, and develop strategies for schedule recovery, including financial feasibility analysis.
This study reinforces the importance of planning and using consolidated methodologies to improve project management in the public sector, allowing for efficient resource utilization and delay reduction. The research showed that even in smaller projects, good management practices yield significant results, serving as a model for other administrations. It is concluded that the objective was achieved: it was demonstrated that the application of the Critical Path Method (CPM) provides a robust procedure for planning and controlling schedules, resulting in greater efficiency and reduced deadlines in public works.
References:
Alves, M. M., Silva, V. S. 2022. Critical Path Method: An Application in the Execution Schedule of a Thickener Tank. Tekhne e Logos 13(3): 1-15.
Brazil. 2024. Report of the Federal Court of Accounts on Public Works. [Note: Reference adapted from the TCC context].
Dangelo, M. J., et al. 2023. Principles of Public Administration in the Contracting of Civil Works. [Note: Reference adapted from the TCC context].
Dey, P. K. 2018. Project Management: A Comprehensive Guide. Routledge, London, UK.
Filho, J. B. A. 2025. Impacts of Civil Construction Projects on Social and Economic Development. [Note: Reference adapted from the TCC context].
G1. 2024. TCU identifies 11.9 million paralyzed public works. Economy. Available at:<https://g1. globo. com/economia/noticia/2024/12/04/tcu-identifica-119-mil-obras-publicas-paralisadas-numero-corresponde-a-metade-dos-contratos-vigentes. ghtml>.
Gil, A. C. 2002. How to develop research projects. 4th ed. Atlas, São Paulo, SP, Brazil.
Kerzner, H. 2017. Project Management: A Systems Approach to Planning, Scheduling, and Controlling. John Wiley & Sons, Hoboken, NJ, USA.
Lock, D. 2021. Project Management. Gower Publishing, Burlington, VT, USA.
Lozada, G.; Nunes, K. S. 2018. Scientific methodology. Sagah, Porto Alegre, RS, Brazil.
Maia, D. F.; Oliveira, R. R. 2018. Approaches and perspectives for schedule management in projects: Analysis of traditional and agile methods. Iberoamerican Journal of Project Management (IJoPM) 9(2): 48-70.
Martins, D. C. 2022. Analysis of the physical schedule of a work using the critical path technique. 45f. Course Conclusion Work (Civil Engineering) – Federal University of Maranhão. Balsa, MA.
Menegazzo, L. G. S.; Maceta, P. 2025. Schedule management applied to the construction of a photovoltaic solar power plant in the city of Cuiabá – MT. PoliUSP. [Note: Reference adapted from the TCC context].
Project Management Institute [PMI]. 2017. A guide to the project management body of knowledge. PMBOK® Guide. 6th ed. Project Management Institute, USA.
Thielmann, R.; Queiroz, K. O. L. 2021. Trade-off between cost and time in projects. Valore Journal 6: 1-15.
Executive summary from the Final Course Work of the Specialization in Project Management of the MBA USP/Esalq
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