Information and communication technology (ICT) tools are ineffective when assessing solutions of questions with more than one step in Mathematics. ICT tools assessing these types of questions are paralleled to solving complex problems. This conceptual paper describes a new combined approach to develop a rule based expert system (ES) prototype, implementing method marking concept (MMC) in assessing multi-step question (MSQ) solutions. Pragmatist views and mixed methods are jointly employed to conduct document analysis using undergraduate students’ solutions to past examination papers and related findings from previous research. Design science research (DSR) paradigm and ES development phases will be used to design, construct and evaluate the artifact based on ES. The expected functioning ES artifact will enhance the authenticity of assessment, because evaluation of solution strategies in MSQ solution reveals the scope in the comprehension of the assessed domain knowledge. The artifact and the conceptual framework can be applied to a similar domain with modifications or as it is.