Corporate environments demand constant output, yet traditional efficiency models accelerate burnout rather than prevent it. The tension between productivity expectations and human capacity has reached a structural breaking point, requiring new frameworks that separate activity from impact. This book examines how organizations conflate busyness with effectiveness, creating systems that reward visible effort over measurable outcomes. It explores three operational mechanisms: task filtering based on strategic alignment rather than urgency, energy allocation across cognitive load cycles, and boundary enforcement within role definitions. Each mechanism addresses a specific failure mode in modern work design-where reactive workflows replace intentional prioritization, where collaboration tools fragment attention, and where availability culture erodes recovery time. The analysis reveals how effectiveness emerges from constraint design rather than capacity expansion. For European markets where work-life integration policies coexist with performance intensity, the book offers a structural lens on sustainable productivity. It positions effectiveness not as personal optimization but as organizational architecture-one that must account for human limitations as design parameters rather than obstacles to overcome.