These three constraints are often competing constraints: increased scope typically means increased time and increased cost, a tight time constraint could mean increased costs and reduced scope, and a tight budget could mean increased time and reduced scope.
Estas tres variábeis están frecuentemente competindo: se aumenta o alcance implica tipicamente que o tempo aumenta e o custo aumenta, unha restrición apertada de tempo podería significar uns custos aumentados e un alcance reducido, e un orzamento apertado podería significar o tempo aumentado e o alcance reducido.