  Artificial Intelligence (AI) is being increasingly used to develop systems
that produce intelligent solutions. However, there is a major concern that
whether the systems built will be trusted by humans. In order to establish
trust in AI systems, there is a need for the user to understand the reasoning
behind their solutions and therefore, the system should be able to explain and
justify its output. In this paper, we use argumentation to provide explanations
in the domain of AI planning. We present argument schemes to create arguments
that explain a plan and its components; and a set of critical questions that
allow interaction between the arguments and enable the user to obtain further
information regarding the key elements of the plan. Finally, we present some
properties of the plan arguments.
