There is no act that is not the coronation of an infinite series of causes and the source of an infinite series of effects - Jorge Luis Borges ”La flor de Coleridge”, in Otras Inquisiciones 1952.
When we seek to produce a credible plan, schedule, cost, or technical performance estimate, we must know the causes of variance and the impact of that variance on the acceptability to sustain successful outcomes from our work efforts.
