Present economic conflicts increase the continues demand for lucrative results that let companies to increase competitive benefit. For this purpose, more establishments look for organizational practices that permit them to enhance their service and/or products features, flawless their procedures, reduce expenses, strengthen the assets productivity and client's gratification. This have been verified through Lean practices and Six Sigma joined methods in their management and manufacture methods in which, Lean attention mostly on the elimination of waste or non-value added process, and Six Sigma on the control and management of process consistency. The integration of Lean and Six Sigma, which is Lean Six Sigma (LSS) is a systematic approach to decrease or eliminate non-value-added process and optimize process variation. The implementation of LSS is laid on 2 fundamental methodologies, the "Define, Measure, Analyze, Improve, Control" (DMAIC) methodology which focuses on process improvement, and the "Define, Measure, Analyze, Design, Verify" (DMADV) methodology for new process invention. Finding from empirical review reveal that prior studies on LSS to view DMAIC and DMADV practices separately. the concept of how DMAIC and DMADV could be integrated for process improvement and new process invention are remains ambiguous. Hence, this paper aims to review the literature of DMAIC and DMADV with the objective to propose the fundamental concept of integrating both DMAIC and DMADV approach into one standard process improvement and invention methodology.