What is a Value Stream and how does it relate to a Value Chain

Value streams and value chains are distinct architectural concepts often confused in practice. Value streams map end-to-end flows across business units to deliver outcomes, enabling optimization through SLAs and bottleneck identification. Value chains, introduced by Michael Porter, decompose organizations into primary and support activities to optimize individual business units. These concepts provide perpendicular viewpoints: value chains focus on vertical, siloed strategic functions, while value streams follow horizontal, cross-functional processes. IT4IT adds complexity by treating IT departments as miniature enterprises with their own value streams and chains, integrating practices from SAFe, ITIL, and TOGAF.