Institute of Artificial Intelligence

Dr. Conny Olz

Conny Olz left Ulm University at the end of 2024. This page is no longer maintained.

I joined the institute in 2019, where my research primarily focuses on the theoretical foundations of hierarchical planning, especially in relation to heuristic search. I completed my PhD under the supervision of Prof. Dr. Susanne Biundo-Stephan and Assoc. Prof. Dr. Pascal Bercher, who is affiliated with the Australian National University (ANU) in Canberra.

Previously, I studied Mathematics (and Management) at Ulm University, with an emphasis on graph theory and combinatorial optimization.

Further Information

  • Theoretical foundations of Hierarchical Planning
  • Domain modelling support
  • Computational complexity theory
  • Post-optimization of partially ordered plans

 

  • Lecture "AI Planning" (WiSe 23/24)
  • Lecture "Knowledge-Based Artificial Intelligence" (WiSe 21/22)
  • Lecture "Intelligente Handlungsplanung" (engl. Automated Planning) (SoSe 21)
  • Lecture "Introduction to Artificial Intelligence" (WiSe 19/20, 20/21)
  • Lecture "Introduction to Computer Science" (SoSe 19)
  • Pro-Seminar "Artificial Intelligence"
  • Seminar "Advances in Artificial Intelligence"
  • Projekt "AI for Autonomous Systems"
  • Project "AI in Games"

 

As a student

  • SoSe 18: Tutor for "Elementare Zahlentheorie"
  • SoSe 16: Tutor for "Optimierung/OR 1"
  • WiSe 15/16: Tutor for "Analysis 1"
  • SoSe 14: Tutor for "Analysis 1"

Bachelor Theses

  • Algorithms for Identifying and Eliminating Redundant Actions in Partially Ordered Plans (2019)
  • Enriching Hierarchical Plans by Extracting Summary Information for Abstract Tasks (2020)
  • Inferring Effects of Compound Tasks in HTN Planning Domains: Implementation and Evaluation (2020)
  • Landmarks and Preconditions and Effects of Compound Tasks – What’s the Connection? (2022)
  • Pruning Utilizing Preconditions and Effects of Compound Tasks in Totally Ordered HTN Planning – An Evaluation (2022)
  • A Heuristic Based on Vector Space Embeddings for Classical Planning (2023/24)
  • A First Approach to Developing Excuses for Unsolvable HTN Planning Problems (2024)
  • Fixing Unsolvable Planning Problems by Modifying Actions (2024)

Master Theses

  • On the Exploitation of Total Order in Partial Order HTN Planning (2021)
  • An Evaluation of Hierarchical Planning Heuristics Using Integer Linear Programming (2023)
  • Development and Evaluation of a Pattern Database Heuristic for HTN Planning (2023/24)
  • Examining Specialized Heuristics for Acyclic Search Nodes in HTN Planning Using Iterative Deepening Depth-First Search (2023/24)
  • Guiding the Expansion of Path Decomposition Trees in SAT-based Totally Ordered HTN Planning (2024)

Program Committee (PC) member or reviewer at conferences:

  • AAAI: 2021, 2024
  • ICAPS: 2023, 2024
  • ECAI: 2024


Program Committee (PC) member at workshops:

  • HPLAN, i.e., Hierarchical Planning: 2020, 2021, 2023

Winner of all three total-order tracks in the International Planning Competition 2023 on HTN Planning. Check the results here.

I have extended the PandaPI-Planungssystem with two new techniques, which are available on GitHub (https://github.com/connyolz/pandaPIengine):

Pruning Technique "Dealer"
  • Dead-End Analysis with Look-Aheads and Early Refinements
  • Published at SoCS 2023
  • GitHub: Branch “dealer”
ILP-based Heuristic "P-Todr"

Publications

2025

17.
C. Olz, A. Lodemann, B. Jutz, M. Schmautz, M. Borowiec, S. Biundo and P. Bercher, "An Extensive Empirical Evaluation of Inferring Preconditions and Effects of Compound Tasks in Ground HTN Planning Problems", Journal of Artificial Intelligence Research, vol. 82, pp. 1407-1444, Mar. 2025. https://jair.org/index.php/jair/article/view/17279.
DOI:10.1613/jair.1.17279
File:https://jair.org/index.php/jair/article/view/17279/27150
16.
M. Welt, A. Lodemann, C. Olz, P. Bercher and B. Glimm, "Calculating Optimal Corrections for Unsolvable Planning Problems" in Proceedings of the 28th European Conference on Artificial Intelligence (ECAI 2025), IOS Press, 2025.
File:/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2025/Welt2025Unsolvable.pdf

2024

15.
C. Olz, A. Lodemann and P. Bercher, "A Heuristic for Optimal Total-Order HTN Planning Based on Integer Linear Programming" in Proceedings of the 27th European Conference on Artificial Intelligence (ECAI 2024), IOS Press, 2024, pp. 4303--4310.
DOI:10.3233/FAIA241005
File:/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2024/Olz24ILP.pdf
14.
C. Olz, A. Lodemann and P. Bercher, "An ILP Heuristic for Total-Order HTN Planning" in Proceedings of the 7th ICAPS Workshop on Hierarchical Planning (HPlan 2024), 2024.
13.
C. Olz, "Exploring the hierarchy: extracting and exploiting state information of compound tasks in HTN planning", 2024.
DOI:10.18725/OPARU-53481
File:https://oparu.uni-ulm.de/items/e6887ad7-6494-4deb-96c4-81edf63cffac
12.
S. Lin, C. Olz, M. Helmert and P. Bercher, "On the Computational Complexity of Plan Verification, (Bounded) Plan-Optimality Verification, and Bounded Plan Existence" in Proceedings of the 38th AAAI Conference on Artificial Intelligence (AAAI 2024), AAAI Press, 2024, pp. 20203--20211.
DOI:https://doi.org/10.1609/aaai.v38i18.30000
File:/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2024/Lin2024PlanVerificationComplexity.pdf

2023

11.
C. Olz and P. Bercher, "A Look-Ahead Technique for Search-Based HTN Planning: Reducing the Branching Factor by Identifying Inevitable Task Refinements" in Proceedings of the 16th International Symposium on Combinatorial Search (SoCS 2023), AAAI Press, 2023, pp. 65--73.
DOI:https://doi.org/10.1609/socs.v16i1.27284
File:/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2023/Olz23Loohahead.pdf
10.
C. Olz and P. Bercher, "Can They Come Together? A Computational Complexity Analysis of Conjunctive Possible Effects of Compound HTN Planning Tasks" in Proceedings of the 33rd International Conference on Automated Planning and Scheduling (ICAPS 2023), AAAI Press, 2023, pp. 314--323.
DOI:https://doi.org/10.1609/icaps.v33i1.27209
File:/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2023/Olz23ConjunctivePossEffs.pdf
9.
Y. X. Wu, C. Olz, S. Lin and P. Bercher, "Grounded (Lifted) Linearizer at the IPC 2023: Solving Partial Order HTN Problems by Linearizing Them" in Proceedings of the 11th International Planning Competition: Planner Abstracts – Hierarchical Task Network (HTN) Planning Track (IPC), 2023.
File:/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2023/Wu2023IPCLinearizer.pdf
8.
S. Lin, C. Olz, M. Helmert and P. Bercher, "On the Computational Complexity of Plan Verification, (Bounded) Plan-Optimality Verification, and Bounded Plan Existence" in Proceedings of the 6th ICAPS Workshop on Hierarchical Planning (HPlan 2023), 2023.
7.
C. Olz, D. Höller and P. Bercher, "The PANDADealer System for Totally Ordered HTN Planning in the 2023 IPC" in Proceedings of the 11th International Planning Competition: Planner Abstracts – Hierarchical Task Network (HTN) Planning Track (IPC), 2023.
File:/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2023/Olz23PandaDealer.pdf

2022

6.
C. Olz and P. Bercher, "On the Efficient Inference of Preconditions and Effects of Compound Tasks in Partially Ordered HTN Planning Domains" in Proceedings of the 5th ICAPS Workshop on Hierarchical Planning (HPlan 2022), 2022, pp. 47--51.
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2022/Olz2022POPrecsAndEffects.pdf
5.
F. Lindner and C. Olz, "Step-by-Step Task Plan Explanations Beyond Causal Links" in 2022 31st IEEE International Conference on Robot & Human Interactive Communication (RO-MAN), IEEE, 2022, pp. 45--51.
DOI:https://doi.org/10.1109/RO-MAN53752.2022.9900590
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2022/Lindner22PlanExplanationBeyondCL.pdf

2021

4.
C. Olz, S. Biundo and P. Bercher, "Revealing Hidden Preconditions and Effects of Compound HTN Planning Tasks – A Complexity Analysis" in Proceedings of the 35th AAAI Conference on Artificial Intelligence (AAAI 2021), AAAI Press, 2021, pp. 11903--11912.
DOI:https://doi.org/10.1609/aaai.v35i13.17414
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2021/Olz21CompoundEffects.pdf
3.
C. Olz, E. Wierzba, P. Bercher and F. Lindner, "Towards Improving the Comprehension of HTN Planning Domains by Means of Preconditions and Effects of Compound Tasks" in Proceedings of the 10th Workshop on Knowledge Engineering for Planning and Scheduling (KEPS 2021), 2021.
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2021/Olz2021ComprehendHTNModels.pdf

2020

2.
P. Bercher and C. Olz, "POP ≡ POCL, right? Complexity Results for Partial Order (Causal Link) Makespan Minimization" in Proceedings of the 34th AAAI Conference on Artificial Intelligence (AAAI 2020), AAAI Press, 2020, pp. 9785--9793.
DOI:https://doi.org/10.1609/aaai.v34i06.6530
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2020/Bercher2020POPvsPOCL.pdf

2019

1.
C. Olz and P. Bercher, "Eliminating Redundant Actions in Partially Ordered Plans -- A Complexity Analysis" in Proceedings of the 29th International Conference on Automated Planning and Scheduling (ICAPS 2019), AAAI Press, 2019, pp. 310--319.
DOI:10.1609/icaps.v29i1.3493
File:pdfhttps://www.uni-ulm.de/fileadmin/website_uni_ulm/iui.inst.090/Publikationen/2019/Olz2019StepElimination.pdf