Job-Scheduling Games with Time-Dependent Processing Times

2026-04-28

AI Summary

This study addresses scheduling games where job processing times linearly depend on their start times—a realistic yet previously unexplored setting relevant to domains such as cybersecurity response and high-frequency trading. The authors establish the first theoretical framework for equilibrium existence in such games: they prove that pure Nash equilibria may not exist in the absence of delay-averse agents, and determining their existence is NP-complete. However, with delay-averse agents, a pure Nash equilibrium can be computed efficiently. For both positive and negative deterioration scenarios, the paper proposes three coordination mechanisms—SBPT, SDR, and LBDR—that bound the Price of Anarchy by a constant factor. Notably, LBDR achieves the tight bound of $\max\{e/(e-1), 2 - 1/m\}$.

Abstract

Job-scheduling games have traditionally assumed fixed processing times. However, in many realistic environments, ranging from cyber-security response to high-frequency trading, a task's duration depends on its starting time. We study job-scheduling games with time-dependent processing times, where job lengths are linear functions of their start times, exhibiting either positive deterioration (increasing length) or negative deterioration (decreasing length). We analyze these games under various coordination mechanisms and priority policies. By introducing the concept of delay-averse agents, we provide a unifying framework to characterize equilibrium existence. For delay-averse jobs, we show that stability is maintained and pure Nash equilibria (NE) can be computed efficiently. In contrast, for non-delay-averse jobs, we demonstrate that a NE may not exist, and prove that deciding its existence is NP-complete, even on identical machines - a fundamental departure from classical coordination mechanisms. Regarding equilibrium inefficiency, we show that the Price of Anarchy (PoA) can be significantly higher than in environments with fixed processing times. To mitigate this, we propose and analyze three coordination mechanisms: SBPT (Shortest Basic Processing Time), which reduces the PoA in games with positive deterioration to a constant, and SDR (Smallest Deterioration Rate) and LBDR (Largest Basic-Deterioration Ratio) for negative deterioration, which achieve tight constant PoA bounds of $2$ and $\max\{\frac{e}{e-1}, 2-\frac{1}{m}\}$, respectively. Our results bridge the gap between centralized time-dependent scheduling and decentralized game-theoretic analysis.

Problem

• job-scheduling games
• time-dependent processing times
• Nash equilibrium
• Price of Anarchy
• coordination mechanisms

Innovation

• time-dependent processing times
• delay-averse agents
• coordination mechanisms
• Price of Anarchy
• Nash equilibrium