Tractable and approximable subclasses

Identify additional polynomially solvable or easily approximable subclasses of the Project Scheduling Interdiction Problem with Delay Groups by exploiting restrictions such as bounded delay-group sizes or special precedence structures.

Background

The paper identifies several tractable cases, including singleton delay groups, antichain groups, and settings in which groups are separated by precedence structure. In contrast, the general problem and important budgeted-uncertainty special cases are NP-hard.

The authors leave open the systematic characterization of further structural conditions under which exact or effective approximate solution methods are possible.

References

Another promising direction is to identify additional polynomially solvable or easily approximable subclasses of PSIP-DG, for instance by bounding delay group sizes or by exploiting special precedence structures.

— The Project Scheduling Interdiction Problem with Delay Groups  (2608.27386 - Wu et al., 27 Aug 2026) in Section Conclusions