The business environment in Tanzania presents a complex set of challenges and opportunities that have evolved significantly over recent decades. Existing diagnostic tools often fail to capture the nuanced, interconnected nature of these factors, particularly for domestic enterprises operating within the local institutional context. This working paper aims to develop and present a novel diagnostic framework specifically designed to assess the health and constraints of Tanzanian enterprises. Its objective is to provide a structured tool for identifying critical bottlenecks across multiple business environment dimensions. The framework is constructed through a synthesis of established business environment theories and longitudinal analysis of policy documents, economic reports, and firm-level survey data. It employs a systems-thinking approach to map interlinkages between institutional, market, and firm-capacity factors. The diagnostic framework identifies infrastructure reliability and access to formal credit as the most frequently interconnected constraint nodes, affecting over 70% of other operational domains. A dominant theme from applying the framework is the critical mediating role of managerial social capital in navigating regulatory hurdles. The proposed framework offers a more holistic and actionable lens for diagnosing enterprise challenges than conventional, siloed analyses. It underscores the systemic nature of business constraints, where isolated interventions are likely to be less effective. Policymakers should utilise integrated diagnostic tools to design coordinated interventions. Enterprise support programmes should prioritise building managerial capabilities in network development and regulatory navigation alongside traditional business skills. business environment, diagnostic framework, enterprise development, institutional analysis, systems thinking, East Africa This paper's novel contribution is the development of a systems-based diagnostic framework that explicitly models the interdependencies between constraints, moving beyond static checklist approaches to offer dynamic assessment for Tanzanian enterprises.