Absolutely positively on time: What would it take?

Amidst the progress made to date in software and hardware techniques, many recent computing advances do more harm than good when embedded computing systems absolutely must meet tight timing constraints. While synchronous digital logic delivers precise timing determinacy, advances in computer architecture and software have made it difficult or impossible to estimate or predict software's execution time. Furthermore, networking techniques introduce variability and stochastic behavior, while operating systems rely on best-effort techniques. Thus, the key to achieving precise timelines in a networked embedded system would be sweeping changes.