Abstract: This study examined the influence of project scope planning on the performance of the Muhanga–Nyange Road Construction Project in Muhanga District, Rwanda. Specifically, the study examined how project scope planning influences project performance. The study adopted a descriptive and explanatory research design. The target population consisted of 349 respondents, and a sample size of 186 respondents was determined using Yamane’s formula. Purposive and simple random sampling techniques were employed to select respondents. Data were collected using structured questionnaires and semi-structured interviews and analyzed using SPSS Version 27. Descriptive statistics, Pearson correlation analysis, and simple linear regression analysis were used to examine the relationship and influence of project scope planning on project performance. The findings revealed that project scope planning was effectively implemented, particularly through clear definition of project objectives and deliverables, communication of project scope, management of scope changes, beneficiary involvement, and implementation of activities according to the approved scope. Correlation analysis indicated a strong positive and statistically significant relationship between project scope planning and project performance (r = .735, p < .001). Regression analysis further demonstrated that project scope planning significantly predicted project performance and explained 54.0% of the variation in project performance. The study concluded that effective project scope planning is an important factor influencing the performance of the Muhanga–Nyange Road Construction Project. The study recommends that project managers and engineers strengthen scope definition, stakeholder consultation, and formal scope-change control procedures to minimize unnecessary variations, delays, and additional project costs.

Dushimimana Jean de Dieu – https://orcid.org/0000-0002-4826-0368

University of Kigali

Email: manidenys25@gmail.com

Abstract: Project constraints management is key to successful implementation of environmental protection projects because success depends on completing activities on time, within budget, and with attainment of intended ecological and social outcomes. The research was anchored on Theory of Constraints and Sustainable Development Theory, and adopted descriptive and correlational research designs with a mixed approach. The target population consisted of 161 stakeholders including project managers, technical staff, environmental officers, and community beneficiaries directly or indirectly involved in the project. A census survey was used, while structured questionnaires, interviews, and documentary review collected primary and secondary data. A pilot test was conducted on 17 respondents, the Content Validity Index was 1.0, and Cronbach’s Alpha was 0.75, confirming validity and reliability of the instruments. Descriptive statistics, Pearson correlation, and regression analysis were applied using SPSS version 28 at a 0.05 level of significance. Findings showed that scope management had a positive and significant effect on sustainability (Beta = .509, t = 9.802, p = .000), time management had a positive and significant effect (Beta = .244, t = 5.127, p = .000), and cost management had a positive and significant effect (Beta = .285, t = 5.858, p = .000). The study concluded that sound management of scope, time, and cost constraints significantly enhances the sustainability of environmental protection projects. It recommended stronger planning, stakeholder involvement, timely execution, and financial control to secure long-term project success.