Improving incident analysis in the Dutch railway sector

1. Improving incident analysisin the Dutch railway sector Mark Dabekaussen (Tebodin Consultants & Engineers) Linda Wright (ProRail) Tjerk van der Schaaf (Eindhoven University of Technology)

2. Overview • What is a SPAD? • Research goal • SPAD analysis methods • Results • Discussion • Study constraints • Conclusions

3. What is a SPAD? Bron: IVW – trendanalyse 2004 A Signal Passed at Danger incidentoccurs when a train driver passes ared signal without permission Number of SPAD’s Year

4. Research goal To determine whether a more comprehensive analysis approach would provide additional insight on the root-causes underlying SPAD incidents. • Existing analysis method: Bow-tie • Alternate analysis method: PRISMA

5. SPAD bow-tie model (1) • Developed to specifically investigate relationships between causes and consequences of SPAD’s • 10 main causal factors (63 sub-cat’s) • Factors similar to those reported in other countries (including UK) • 10 possible consequences • Possible to include multiple causes and multiple consequences!

6. SPAD bow-tie model (2) Signal perception Only financial consequences Previous signal perception No injuries Braking operation Material damage Minor injuries personnel and/or passengers Network Control process Communication Serious injuries personnel and/or passengers Expectations Death to personnel and/or passengers Information processing Further escalation – fire, explosion etc. Driver actions Collision – damaged infrastructure Network Controller actions Collision – level crossing Contributing factors Derailment SPAD Incident

7. PRISMA Basic components: Analysis: Causal trees Result: Root-causes Classification: Eindhoven Classification Model Result: Profile of root causes Countermeasures: Classification / action matrix Output: Appropriate countermeasure(s)

8. Requirements of a Taxonomy

9. Method of Analysis (1) Analysis using the Bow-tie model Aim: to translate bow-tie causes into applicable PRISMA categories Method: algorithm constructed by bow-tie analyst Dataset: 69 incidents selected from 2003 incident set Reliability: inter-rater reliability trials for both data and algorithm

10. Method of Analysis (2) Analysis using the PRISMA method Aim: examination of effectiveness of analysis Method: reanalysis of data using causal-trees & PRISMA classification Dataset: same 69 incidents selected from 2003 incident set Reliability: inter-rater reliability trial of analysis and classification

11. Results

12. Discussion (1) • Significant differences in the types of root-causes being found using PRISMA vs. SPAD Bow-tie model • Not all information being used in analysis (i.e. focus on “active” rather than “latent” errors)

13. Discussion (2) • Bow-tie analyst admitted to further interpretation of data • Difference in complexity of analysis- supported by tentative results of 3rd study PRISMA analysis SPAD Bow-tie analysis Root cause Causal factor Causal factor Causal factor Root cause Root cause

14. Study constraints • No examination of recovery factors • No examination of specific consequences • Limited information in dossiers, did not enable a full PRISMA analysis • Accuracy of information in dossiers

15. Conclusions • Current SPAD analysis process is not as effective as possible • Primary focus on staff and little focus on org./tech. factors • Including multiple causes in incident analysis is an insufficient qualification for effective analysis Underlying taxonomy must meet minimum set of criteria

16. Questions? Cuestiónes? Fragen? Вопросы? Vragen? Ερωτήσεις? Pregunta?