Companies specialized in software development services and software outsourcing have adopted agile methodologies such as SCRUM and Kanban to drive the software development process. Along time, experts have introduced new methodologies that enhance agile roadmaps with lean patterns and design thinking tools. Despite the value added brought by aggregation of agile with lean and design thinking, the integrated methodology is still fuzzy at operational level. There is no scientific demonstration on the most appropriate way to alternate the steps of agile with those promoted by lean innovation and design thinking. This niche of opportunity is investigated by this paper. Conflicts and barriers generated by aggregation are treated with TRIZ. Inventive solutions are proposed to optimize the agile-lean-design thinking (ALDET) software development process considering a life-cycle perspective. Gaps identified in ALDET are additionally tackled with TRIZ and new tools of competitive engineering, including TRIZ contradiction matrix for software, are embedded within the optimized ALDET to enhance its potentiality. The methodology is called Competitive ALDET or CALDET. Its effectiveness was tested in a real project. Preliminary results demonstrate that CALDET provides a clearer and smoother path for project management, reduces ambiguities relative to traditional ALDET methodology, and increases the impact of outcomes to the user. By tackling conflicts in an iterative manner, CALDET avoids re-analysis and re-coding in software development, too. The presence of value engineering tools within the framework of CALDET reveals additional spaces of innovation, both technical and project management related.