[Retracted] Maintenance Methodologies Embraced for Railroad Systems: A Review

Table 2

Inferences of statistical track maintenance methods.

Author Reference	Evaluation Scheme	Concentrated segment	Parameters involved	Tools employed	Research gap
[5]	Case study	Track maintenance	Frequency of tamping operation	Mixed integer programming model (MILP)	Cost structure/schedule generation
[6]	Case study	Track maintenance	Rail grinding schedule/rail crack detection	Integer programming model (ILP)/polyhedral analysis	Maintenance decision-making process/frequency of inspections
[24]	Case study	Track geometry	Inspection/intervention/renewal	Petri net formulation	Track length/tamping machine
[25]	Real time	Track maintenance	Segments/routine works/possession cost	TMS strategy/Sensitivity analysis	Calibration of the PMSP model
[29]	Case study	Track maintenance schedule	Maintenance activities/risk assessment	Modular model architecture/ILP	Online recovery tool to determine stochastic delays
[32]	Case study	Track degradation	Rail load, rail type, rail profile	Adaptive network-based fuzzy inference system (ANFIS) model	Gauge value prediction
[33]	Case study	Track maintenance	Time period/track component replacement	Integer programming model (ILP)/Heuristic algorithms	Unexpected interventions/corrective maintenance decisions
[36]	Case study	Track maintenance	User cost/environmental cost	RAMS/LCCA	Database management
[37]	Case study	Track maintenance	Ballast type/lab test/traffic	Life cycle approach	Life cycle cost analysis (LCCA) and life cycle assessment (LCA)
[38]	Case study	Track maintenance	Rail, ballast, sleepers, and switches	Binary integer programming (IP) model	Limitation of possession time
[39]	Real time	Track maintenance clustering	Project duration/job cluster type	Mixed integer mathematical programming model (MIMP)	Randomness of algorithm
[40]	Case study	Track interactive rolling sets	Wheel diameter/mileage	Markov decision process/MDP toolbox-MATLAB	Markov transition matrix (MTM)/inspection modes/precision
[41]	Case study	Track maintenance	Rail grinding/renewal	Markov decision process	Rail curvature