September 30, 2026
Schedule Management for Solar Tracking Structures Implementation Project
Schedule Management for Solar Tracking Structures Implementation Project
Bruna Bonatto Buffon; Nadia Valério Possignolo Vitti
DOI: 10.22167/2675-6528-202602731
Article derived from a Course Conclusion Work (TCC), with content based on the student’s original work and adapted to the editorial format of the E&S Magazine with the support of the ResumeAI tool, an artificial intelligence solution developed by Instituto Pecege for textual synthesis and organization.
Summary
Photovoltaic solar energy has a growing position in the Brazilian electricity matrix, with solar tracking structures being an installation alternative that can be managed by a project with structured schedule premises. The objective was to describe the schedule management, according to the best practices of the PMBOK Guide, for a solar tracking structure implementation project. A descriptive, qualitative research was carried out, with a case study design. The process groups of Initiation, Planning, and Monitoring and Controlling in the Schedule Management Area were considered. The methods employed included the definition and sequencing of activities based on the Work Breakdown Structure (WBS), the determination of durations by the PERT method, the identification of the critical path and the construction of the Network Diagram, the elaboration of the Gantt Chart with the Project Libre® software, and the monitoring of progress through the S-Curve. 28 activities were identified, distributed in three main deliverables. The total estimated project duration was 113.90 days, with a standard deviation of 8.11 days and a safety margin of 13.34 days, with 95% confidence. Monitoring by the S-Curve showed a divergence between the planned and actual progress as early as the second week of the project. The structuring of schedule management proved to be fundamental for aligning expectations, identifying bottlenecks, and building a historical basis for future projects in the photovoltaic solar energy sector.
Keywords: critical path; S-curve; solar photovoltaic energy; PMBOK Guide; PERT.
1. Introduction
The consumption of energy, in its various forms, is intrinsic to the daily lives of millions of people, sustaining the convenience associated with the contemporary lifestyle. Whether for refrigerating food, using public transport, connecting to the internet, or turning on a light bulb, the need for electrical energy is the common thread that connects these activities.
In Brazil, the electricity generation matrix is predominantly composed of renewable sources, representing 86.8% of the total, with solar energy contributing 9.3% (EPE, 2025). This participation reflects the country’s vast availability of natural resources and aligns with clean energy generation commitments (Petrobras, 2025).
Photovoltaic solar energy, in particular, has gained familiarity, with the possibility of installing plants in residences (Brazil, 2022). In medium or large-scale installations, especially on the ground, solar tracking structures, known as “trackers”, are used. These systems allow the movement of the mounting structure on one or more axes to follow the sun’s movement throughout the day, maximizing energy generation (Sunne, 2023).
The implementation of these solar tracking structures is, by its nature, a project. Given the variety of terrain conditions and embedding methods, each solution is designed and produced specifically for each work. This process involves everything from technical alignment and drawing production, to manufacturing, logistics, pile fixing, team training, assembly, commissioning, and technical support.
Considering the finiteness and unique outcome of a project, its cohesive management aligned with objectives can lead to more satisfactory results (PMI, 2017). In this context, the methodologies and best practices of the Project Management Body of Knowledge (PMBOK) Guide are applicable, especially in Time Management, which is crucial for successful delivery.
Despite the complexity and the diverse elements that make up the supply of solar tracking solutions, the application of structured schedule management is not a common practice in the sector. Currently, the management of these supplies is often based on milestone schedules, which can lead to a perception of delays and high variability in project execution, as observed in previous experiences.
The absence of a standardized method for information collection and monitoring the progress of activities contributes to this unpredictability and hinders informed decision-making. The implementation of schedule management, according to PMBOK best practices, is fundamental for clearly defining objectives, synthesizing activities, documentation, and follow-up, allowing for continuous monitoring and improvement. This builds a valuable historical base for future projects, aligning expectations and proactively identifying bottlenecks.
Given this scenario, the present work is justified by the need to improve the predictability and efficiency in the implementation of solar tracking structures. The objective of the present work was to describe the schedule management, according to the best practices of the PMBOK Guide, for a project of implementation of solar tracking structures.
2. Material and Methods
The research conducted was characterized as descriptive, qualitative in nature, with a case study design. The focus was the report of reality without researcher interference, using observations, interrogations, collections, analyses, comparisons, and records to characterize the phenomenon studied (Campos, 2008). The aim was to understand the elements and their occurrence throughout the project, without the intention of quantification (Gil, 2002).
The case study design was adopted because it is based on an in-depth and detailed analysis of a specific macro-project, which served as the unit of analysis (Gil, 2017). The empirical object was the schedule management for the implementation of solar tracking structures, according to the best practices of the PMBOK Guide.
The project studied was the implementation of solar tracking structures at the Brasília Photovoltaic Solar Power Plant (UFV), located in the city of Brazlândia, in the Federal District. The company responsible for conducting the project is a multinational company specialized in solar tracking solutions. The scope of the research focused on the implementation sector, covering activities from the arrival of materials in the field to the completion of the installation and acceptance of the solution by the client.
The execution period of the complete project, from sale to completion of implementation, extended from July 15, 2022, to July 08, 2025. For the preparation of the schedule in the specific software, the start date considered was March 10, 2025, aligned with the actual start of the field structure implementation.
For the execution of the present work, the process groups of Initiation, Planning and Control and Monitoring were considered, according to the Knowledge Area of Schedule Management of the PMBOK Guide (PMI, 2017). The company’s data and information were used with formal consent, ensuring the ethical aspects of the research.
In the Initiating phase, information pertinent to the project was documented in a Project Charter (TAP). This document formalized the project, describing it, establishing its purpose, assumptions, justification, measurable objectives, success criteria, stakeholders, expected benefits, approval requirements, termination criteria, timeline, project constraints and limits, as well as identifying risks.
The Planning stage involved defining the scope, refining the objectives, and identifying the necessary actions to achieve them (PMI, 2017). Scope Management ensured that all the work required to complete the project was included, being formalized through a Scope Statement. This document detailed the project and its associated product, outlining its boundaries and acceptance criteria.
The Work Breakdown Structure (WBS) was used to resize the work into easily manageable components, providing a structured view of the deliverables needed for project completion (PMI, 2017). The WBS identified 28 activities distributed across three main deliverables, with some work packages being the client’s responsibility.
The definition of activities was based on the deliverables of the WBS (Work Breakdown Structure), identifying and documenting the actions to be performed (PMI, 2017). The sequencing of activities was carried out using the Precedence Diagramming Method (PDM), establishing the logic of the relationship between tasks and enabling a visual representation of the operational sequence.
The estimation of activity durations considered historical data from similar projects and applied the Three-Point Estimation (PERT), which evaluates optimistic, pessimistic, and most likely scenarios. The average duration of each activity (DE) was calculated by the formula (o + 4m + p) / 6, where ‘o’ is the optimistic estimate, ‘m’ the most likely, and ‘p’ the pessimistic.
The standard deviation (SD) of each activity was determined by (p – o) / 6, and the variance (Var) as SD². The total estimated project duration (Total ED) was the sum of the average durations of the activities on the critical path (∑ Avg ED CP). The total project variance (Total Var) corresponded to the sum of the variances of the activities on the critical path (∑ Var CP).
The total standard deviation of the project (Total SD) was obtained by the square root of the total variance. For the calculation of the safety margin, a safety factor for two deviations was considered, resulting in Total SD multiplied by 1.645, ensuring 95% confidence in the project’s completion within the established deadline.
The development of the schedule involved allocating activities to the calendar, aligning them with delivery expectations. For this purpose, the software ProjectLibre®, version 1.9.8, was used. This software allowed for the creation of the Gantt Chart, which visually represented the distribution of tasks over time, and the construction of the Network Diagram, which outlined the project’s critical path.
In the Controlling and Monitoring phase, the project’s situation was verified at defined intervals for schedule updates and change management (PMI, 2017). The monitoring of activity progress was carried out by constructing an S-Curve, which allowed for the comparison between the planned and actual cumulative progress of the project.
3. Results and Discussion
This section details the findings and interpretations arising from the application of the PMBOK Guide best practices to the schedule management of a solar tracking structure implementation project. The results obtained allowed for an in-depth understanding of the schedule’s structuring, from defining activities and estimating their durations to monitoring progress, highlighting both the effectiveness of the tools and the challenges inherent in managing complex projects in the photovoltaic energy sector. The analysis focused on the description of planning and control, as established in the objective.
The project initiation process was formalized through a Project Charter, which outlined the scope, measurable objectives, and success criteria. This document established the purpose of implementing tracking structures at the Brasília Photovoltaic Solar Power Plant to optimize energy potential, as well as providing for client team training and compliance with technical standards. Assumptions included the absence of significant delays due to rain or lack of concrete, quality supervision, and the expectation that no defects would be found during commissioning.
The project’s Scope Statement, in turn, detailed the measurable objectives, such as the deployment of autonomous structures operating within contractual deadlines and the confirmation of complete material receipt within fifteen days. Success criteria were also defined, such as formally accepted deliverables and milestones, signed critical documentation, and company labor-dependent activities completed on time. The project’s justification lies in the better utilization of solar energy, revenue generation, and consolidation of the company in the Brazilian market, according to project management literature (PMI, 2017).
The Work Breakdown Structure (WBS) was fundamental in breaking down the work into manageable components, organizing the deliverables necessary for project completion. Three main deliverables were identified: Training and Meetings, Installation and Assembly, and Commissioning. Within these deliverables, work packages were detailed, with packages 1.2.2 to 1.2.6, related to the assembly of the structure, identified as the client’s responsibility, which introduced a layer of complexity and risk to the overall schedule.
Schedule Management Planning
Definition of Activities
From the WBS (Work Breakdown Structure), it was possible to identify and list 28 distinct activities, each with its respective resources, essential for the delivery of each work package. For example, activities such as “Obtain contacts and execution schedule from the Client” (ID 4) and “Inspect all received material” (ID 7) were defined with specific resources, such as the Site Manager and the Client Warehouse Keeper. The allocation of resources, such as “Client Bricklayer and Helper” or “Client Assembler and Helper”, was planned in pairs for work packages 1.2.2 to 1.2.6, aiming for safety on uneven and difficult-to-access terrain, which directly impacts communication and task progress.
The role of the “Site Manager” as a single resource in various simultaneous activities was identified as a potential risk, as their eventual replacement in the field would consume time and could cause delays in critical project phases. The absence of a standardized method for collecting and storing information on activity progress, relying on informal reports from different “Site Managers” and clients, resulted in data dispersion and variation, hindering uniformity in progress reporting and the use of this data for future projects.
Sequencing and Duration of Activities
The sequencing of activities considered the logic of installation and commissioning, as well as the execution logistics. The Precedence Diagramming Method (PDM) was applied to establish the logical relationships between activities. The estimation of durations was carried out using the Three-Point Estimate (PERT), which considers optimistic, most likely, and pessimistic scenarios, allowing for a more precise determination of the time required for each task, according to the equations for calculating average duration, standard deviation, and variance.
The total estimated project duration was 113.90 days, with a standard deviation of 8.11 days and a total variance of 65.80 days². To ensure a high probability of completion within the deadline, a safety margin of 13.34 days was calculated, with 95% confidence. This margin is crucial for absorbing unforeseen events, especially in activities for which the client is responsible, which historically show greater variability and uncertainty.
A significant finding was the 89.8% difference between the estimated project duration (113.90 days) and the 60-day deadline set in the Project Charter for the implementation phase. This discrepancy indicates the company’s general perception that deadlines allocated for implementation are rarely met, which impacts stakeholder relationships and increases the risk of poor resource allocation even before activities begin.
The logical sequencing of activities was based on the project history and contractual premises. For example, the visual inspection of the installation activity (ID 36) depends on the completion of the installation and client request, with a contractual delay of seven days for displacement. The concreting of piles (ID 18) was planned to start three days after alignment (ID 17), allowing for the accumulation of piles for the order of a concrete mixer truck, a common practice in the activity.
The remote monitoring of the installation activity (ID 15), which spans 46.67 days, begins one day after schedule alignment (ID 4) and concludes with minimum quality verification (ID 32). This company-responsible activity aims to track the progress of the client’s activities, which are crucial for the project’s advancement. The duration of this activity in the schedule reflects the need to cover the entire period of the structure’s installation activities.
Schedule Development
The listing and sequencing of activities, along with resource allocation, were entered into the ProjectLibre® software, with the project start date of March 10, 2025. This effort resulted in the automation of the schedule, allowing for visualization and correction of errors. The Gantt Chart, generated by the software, visually outlined the project’s unfolding, its critical path, and the foreseen progress over time.
The Gantt Chart proved to be a valuable tool for visualizing the set of activities and their temporal distribution, with the critical path highlighted in red. Its main benefits include visualizing the connections between activities, making stakeholders aware of their role in the final delivery, communicating development expectations, and providing quick access to the schedule to identify critical activities and manage risks and resources. However, in very extensive or dynamic projects, the update effort may outweigh the benefits, and field conditions may hinder visual access to the tool.
The Network Diagram, in turn, facilitated the visualization of the logical chaining of the critical path, allowing the identification of tasks that, if delayed, immediately compromise deadlines. This feature, according to Mattos (2010), is essential for understanding the urgency of activities and supporting decision-making on action plans in case of delays. Both the Gantt Chart and the Network Diagram are dynamic tools that require constant monitoring and updating to reflect the real progress of the project and support the redirection of activities and team restructuring.
Schedule Control and Monitoring
The project progress monitoring was carried out using the S-Curve, which compared the planned and actual cumulative progress. In the first fourteen days, the S-Curve indicated an advancement of field activities, focused on cable pulling (activity 1.2.5.2). This advancement, although dependent on weather conditions and machinery availability, was possible without additional risks, even though the activity could not be fully completed without the installed tracking structure.
The baseline schedule predicted the completion of activities on June 26, 2025. However, the project was completed on July 08, 2025, resulting in a delay of 13.4 days. It is noteworthy that the calculated safety margin of 13.34 days, with 95% confidence, coincided with the actual project delay. By summing the planned duration (113.90 days), the standard deviation (8.11 days), and the safety margin (13.34 days), the total duration aligned with the most conservative expectations was 135.35 days, differing by only 0.65% from the actual execution duration (134.38 days), which suggests good predictability of the PERT methodology.
Despite the total delay, the acceptance criteria of the Scope Statement were met, as the activities exclusively the company’s responsibility were executed within the established deadline, even if reallocated to later dates. The delay was demonstrably associated with activities the client’s responsibility. This distinction is fundamental for the interpretation of the project’s success, reinforcing the importance of clearly defining the scope and responsibilities in the initiation phase.
However, monitoring by the S-Curve presented limitations, as the 28 activities were not valued according to their importance or criticality. This means that the tracked progress did not consider the weight of the critical path activities, which could distort the perception of real progress. Mattos (2010) suggests weighting the completion of activities based on hours worked or costs, which was not possible in this study due to the absence of consistent data and the lack of total control over client activities.
The monitoring process was also compromised by the client’s reliance on the “Site Manager” for feedback, resulting in weeks without updates on activity progress. The lack of a robust communication protocol and asynchronous tools for data collection contributed to this failure. Although the schedule’s structure was promising for planning, monitoring during execution highlighted the need to improve communication and standardized information gathering for more effective risk and deviation management.
In summary, applying the best practices of the PMBOK Guide to the schedule management of the solar tracking structures implementation project revealed the importance of formalizing the initiation and planning stages to establish a clear project vision. The use of tools such as the WBS (Work Breakdown Structure), PERT method, Gantt Chart, and Network Diagram allowed for the identification of 28 activities, estimation of a total duration of 113.90 days with a buffer of 13.34 days, and visualization of the critical path. Although monitoring by the S-Curve showed a delay of 13.4 days, which coincided with the buffer, the methodology’s predictability was confirmed, and the analysis highlighted the need to improve client communication and activity weighting in monitoring for future projects.
4. Conclusion
This study aimed to describe schedule management, according to the best practices of the PMBOK Guide, for a solar tracking structures implementation project. It was found that the application of these practices, from initiation, with the formalization of the Project Charter and Scope Statement, to detailed planning, was fundamental for structuring the project. Through the Work Breakdown Structure, 28 activities were identified, distributed across three main deliverables. The duration estimate using the PERT method indicated a total timeframe of 113.90 days, with a buffer of 13.34 days for 95% confidence, which contrasted significantly with the initial timeframe of 60 days. It was observed that tools such as the Gantt Chart and the Network Diagram facilitated the visualization of the critical path and the logical sequencing of tasks. Monitoring by the S-Curve showed a divergence between planned and actual progress as early as the second week, and the project was completed with a delay of 13.4 days, a value that aligned remarkably with the calculated buffer, confirming the predictability of the methodology. The main contribution lies in demonstrating that the structuring of schedule management is essential for aligning expectations, proactively identifying bottlenecks, and building a robust historical base for future ventures in the solar photovoltaic energy sector.
However, limitations were identified in the monitoring process, mainly due to the absence of consistent data for valuing the importance or criticality of each of the 28 activities in the S-Curve, which may have distorted the perception of real progress. The reliance on client feedback for activity progress also compromised the uniformity and frequency of monitoring, highlighting the fragility of existing communication protocols. For future studies, it is recommended to implement a weighting of activities in the S-Curve monitoring, considering their criticality and impact on the critical path. It is also suggested to develop a more robust communication protocol and adopt asynchronous tools for standardized data collection, aiming to improve risk and deviation management and strengthen predictability in subsequent projects.
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Article originating from the Final Course Project of the Specialization in Project Management of the MBA USP/Esalq
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