Table 1.

Summary of reviewed vehicle routing and scheduling optimisation models for emergency relief.

Study	Resource	Sequence	Mode	Objective	Solution	Model Limitation
Chang et al. [36]	Expendable	–	Stochastic	To minimise transportation cost, facility set up cost, equipment cost	Exact method	–Sequencing and scheduling of resources are not considered
Balcik et al. [37]	Expendable	Known	Stochastic	To maximise total expected demand	Exact method	–Assumes sequence of visit is known
						–The only sequencing/routing decision is whether the node should be visited each day
Huang et al. [45]	Expendable	Unknown	Deterministic	To minimise total travel time, sums of arrival times and unsatisfied demand	Heuristic method	–Considers only a single type of expendable resource
Falasca and Zobel [40]	Non-expendable	–	Deterministic	To minimise cost of task shortage, total number of undesired tasks and time blocks	Exact method	–Sequencing and scheduling of volunteers are ignored
Lee et al. [3]	Both	Known	Deterministic	To minimise total weighted tardiness	Heuristic method	–Assumes sequence of visit to demand points is known in advance
						–Difference in quantity of non-expendable resources to be delivered is ignored
Wex et al. [15]	Non-expendable	Unknown	Deterministic	To minimise total weighted completion times	Heuristic method	–Assumes identical unit and ignores the different types and quantities of non-expendable resources to be delivered
						–Model is non-linear programming
Schryen et al. [42]	Non-expendable	Unknown	Stochastic	To minimise total weighted completion times	Heuristic method	–Assumes difference in quantity of non-expendable resources is negligible
						–Model is non-linear programming
Lei et al. [1]	Both	Known	Deterministic	To minimise total weighted tardiness	Heuristic method	–Assumes sequence of visit to demand points is known in advance
						–Difference in quantity of non-expendable resources to be delivered is ignored
Caunhye et al. [47]	Expendable	Unknown	Stochastic	To minimise cost of setting up warehouse, total response time	Exact method	–Only one type of expendable resource is considered
						–Response time is calculated based on transportation time
Shahparvari and Bodaghi [44]	Both	Known	Deterministic	To minimise operational costs of the vehicle fleet	Heuristic method	–Assumes sequence of visit to demand points is known in advance
						–Uses fuzzification to generate inexact variable values, such as time windows and risk levels
Bodaghi et al. [48]	Both	Unknown	Probabilistic	To minimise weighted completion time	Exact method	–The model could be applied for small to medium size case studies