# Systematic Review on the Use of CCPM in Project Management: Empirical Applications and Trends
Traditional project management methods often lack effective control and monitoring mechanisms, which leads to project failures. A lack of real-time data visibility and reliance on manual methods can result in delays, miscommunication, and inefficiencies [2]. Several factors, including labor, materials, equipment, site characteristics, management, finances, economic conditions, and work accidents, among others, can generally cause delays in project execution [3, 4]. The condition generated by delays and difficulties in managing resources generates the need for a more effective project management strategy [5]. Recent studies have highlighted the potential for integrating CCPM with emerging methodologies such as BIM, Lean Construction, and predictive tools based on artificial intelligence, thereby expanding its scope of application [6, 7, 8, 9, 10, 11]. In response to such challenges, in 1997, [PERSON] proposed a method based on the foundations of the Theory of Constraints (TOC), called Critical Chain Project Management (CCPM) [12]. The TOC method is used to manage project uncertainties, structure time buffers to absorb variability in task execution, and manage resources. CCPM is used in various types of industries and businesses, such as power plant projects [13], the construction industry [5, 14], manufacturing [15], the oil and gas energy industry [16], and information technology projects [17], among others [18]. Given the above, the following research question arises: What are the main applications of CCPM in the literature, and what are the main results? Therefore, this article aims to critically analyze the theoretical and practical contributions of the recent literature on CCPM in multi-project environments through a systematic review. The study seeks to identify methodological trends, application gaps, and potential directions for future research. To carry out this research, a systematic literature review was carried out on this approach to managing projects that are still young (less than 30 years old) and on the application of the CCPM technique with other tools, methods, and approaches, such as the combined application of Scrum and CCPM [19], joint application of Building Information Modeling (BIM) tools and CCPM [6], organization and management of multi-project activities and resources [20], development of new products and management of their portfolio [21, 22], project management, considering rework [23], demonstrating the flexibility and quality of the CCPM method. The results highlighted research gaps and opportunities for future studies, such as applications for manufacturing companies operating under the Engineer-to-Order (ETO) production system, as well as service companies. Engineer-to-Order (ETO) environments are characterized by high product customization, dynamic engineering requirements, and unpredictable workflows, making conventional project control techniques less effective. These attributes generate intense scheduling variability and resource conflicts, which CCPM may help mitigate by prioritizing constraints and buffer management [24]. This article contains the following sections: methodology, results, discussion, and final considerations.