To increase maturity in SDLC is is generally recommended to implement the Primary SDLC processes. If you already have these processes fully optimised and have reached Maturity Level 5, it is time to implement the Supporting and Organisational processes. See Maturing your SDLC for more details.
When we think about SDLC we tend to align our project phases with key activities such as conception, requirements, design, build, test, deployment and then maintenance. SDLC is more than that. It is a question of how well an organisation performs these activities and whether performance is being measured. If you can measure how well you do requirements for example, naturally you can expect efficiencies in subsequent project phases. The question therefore becomes how does SDLC align with project management methodology? Project Management methodologies deal well with schedule and deliverables. To increase quality factors concerning the product delivered as a result of doing the project, particularly in an Agile context, requires a collaborative approach. The following chart depicts how SLDC is related to project phases.
