If you’re new to project management or building your confidence at the mid-level, you’ve likely heard both terms: “Project Life Cycle” and “Development Life Cycle.” Sometimes they get used interchangeably, but make no mistake: these two concepts serve different purposes, involve different stakeholders, and guide different phases of work. Knowing the difference can help you better plan, execute, and communicate on your projects—especially when working across cross-functional teams.
In this guide, we’ll walk through what each life cycle involves, how they relate, and why understanding both is essential to successful delivery.
What Is the Project Life Cycle?
The Project Life Cycle (PLC) represents the high-level phases a project goes through from initiation to closure. Regardless of the industry or methodology used (Waterfall, Agile, hybrid), every project typically follows this structure:
- Initiation
- Planning
- Execution
- Monitoring & Controlling
- Closure
Let’s look at each stage briefly:
1. Initiation
This is where the project is formally started. It involves:
- Defining the business need or opportunity
- Conducting feasibility studies
- Establishing high-level scope and objectives
- Securing initial stakeholder approval and funding
Deliverables: Project Charter, Stakeholder Register
2. Planning
Here, the roadmap is built. Planning includes:
- Defining scope, time, and cost baselines
- Creating schedules and resource plans
- Identifying risks and mitigation strategies
- Establishing communication and quality plans
Deliverables: Project Management Plan, Risk Register, WBS, Gantt Charts
3. Execution
This is where work gets done according to the plan. Key elements:
- Assigning tasks and managing teams
- Tracking performance and deliverables
- Managing stakeholder engagement
Deliverables: Status reports, issue logs, deliverables as per project scope
4. Monitoring & Controlling
This overlaps with execution and includes:
- Tracking KPIs and progress
- Managing changes to scope, budget, or timeline
- Ensuring quality standards are met
Deliverables: Change Requests, Performance Metrics, Quality Reports
5. Closure
The project is wrapped up with:
- Final deliverables handed off
- Lessons learned captured
- Contracts closed
- Team and stakeholder debriefs
Deliverables: Final Project Report, Lessons Learned Document, Client Sign-off
Key Point: The Project Life Cycle is concerned with managing the project as a whole—not necessarily the specific technical process of building a product or system.
What Is the Development Life Cycle?
The Development Life Cycle (DLC) refers to the process used to design, build, test, and deliver the solution that the project exists to create. It often varies based on what you’re developing:
- In software development, it’s called the Software Development Life Cycle (SDLC)
- In product development, it’s the Product Development Life Cycle
- In construction, you might hear terms like design-build or engineering development cycles
For this blog, we’ll focus primarily on the SDLC model, as it’s the most common use case for project managers working in tech or digital environments.
Common SDLC Phases:
- Requirements Gathering & Analysis
- Design
- Development (or Implementation)
- Testing
- Deployment
- Maintenance
1. Requirements Gathering
This is where the technical team defines what the system needs to do. It involves:
- Interviews with users and stakeholders
- Reviewing business processes
- Documenting functional and non-functional requirements
Deliverables: Requirements Specifications, User Stories
2. Design
The architecture of the system is developed here, including:
- System models
- Interface designs
- Data architecture and technology stacks
Deliverables: Technical Design Documents, Wireframes, ER Diagrams
3. Development
This is the coding or building phase:
- Developers write and integrate code
- The design is turned into a working system or application
Deliverables: Source Code, Software Builds
4. Testing
Quality assurance happens here:
- Functional, performance, and security testing
- User acceptance testing (UAT)
- Bug tracking and fixing
Deliverables: Test Plans, Bug Reports, QA Sign-off
5. Deployment
The product goes live:
- Released to production
- Go-live planning and stakeholder notifications
Deliverables: Deployment Guides, Release Notes
6. Maintenance
Post-deployment support:
- Monitoring system performance
- Handling updates and patches
- Responding to user feedback and bug reports
Deliverables: Support Logs, Maintenance Reports
Key Point: The Development Life Cycle is focused on building the product or system itself.
So, How Do They Interact?
Here’s where many junior project managers get tripped up: thinking of PLC and DLC as parallel tracks. In reality, the development life cycle lives within the execution phase of the project life cycle.
For example:
- During Project Planning, you may plan timelines that include each development phase.
- During Project Execution, the team will follow the development life cycle to build the product.
- Your Monitoring phase tracks how well the development work is progressing.
A well-managed project ensures that development milestones align with overall project goals, budget, and stakeholder expectations.
Diagram (text format):
Project Life Cycle:
[Initiation] → [Planning] → [Execution] -- [Development Life Cycle] --> [Monitoring] → [Closure]Common Methodologies and Frameworks
Understanding life cycles also means recognizing the frameworks that structure them.
Project Management Frameworks:
- PMBOK (Project Management Institute)
- PRINCE2
- Agile Project Management (AgilePM)
Development Frameworks:
- Waterfall
- Agile (Scrum, Kanban, SAFe)
- DevOps
A Waterfall project might map development and project stages linearly, while an Agile team might iterate through development cycles within a broader project timeline.
Agile Note: In Agile, the concept of a linear “Project Life Cycle” can blur. Instead of one big initiation-planning-execution cycle, you may run sprints or releases that loop through mini life cycles of planning, developing, testing, and delivering.
Why This Matters to Junior and Mid-Level PMs
- Better Stakeholder Communication When you can distinguish between project stages and development stages, you can more clearly explain timelines and dependencies to both business and technical stakeholders.
- Improved Planning Accuracy Understanding the development life cycle helps you plan execution activities with greater precision, especially when working with engineering or IT teams.
- Smarter Risk Management Knowing how and when system design or testing fits into the broader project helps you anticipate delays, resource bottlenecks, and integration risks.
- Stronger Change Control Changes in requirements can impact development differently than project schedules. Understanding both life cycles helps you evaluate change impacts more thoroughly.
- Career Growth The ability to speak both “project” and “development” fluently sets you apart. It positions you as someone who can bridge business goals and technical delivery.
Final Thoughts: Bridging Two Worlds
The Project Life Cycle is your roadmap for managing the work. The Development Life Cycle is your blueprint for building the solution.
As a junior or mid-level project manager, you don’t need to be a developer or architect—but you do need to understand how their work fits into the bigger picture. The more comfortable you are with both life cycles, the more effective you’ll be in coordinating teams, meeting deadlines, and delivering results that matter.
Key Takeaways:
- PLC = Managing the overall project
- DLC = Building the solution within the project
- Development activities live inside the Execution phase of a project
- Aligning the two life cycles helps avoid surprises, rework, and miscommunication
Mastering the distinction doesn’t just improve your PM skills—it sharpens your leadership edge. Stay curious, stay clear, and always know which life cycle you’re in.