Agile vs. Waterfall for Satellites: An MBSE Simulation in Innoslate

Robin Yeman and Yashwant Malaiya recently demonstrated MBSE for Satellite systems using Innoslate as their MBSE tool. They presented their study at the 22nd Annual Acquisition Research Symposium and Innovation Summit, hosted by the Naval Postgraduate School. The research, titled “Accelerating Satellite Development: A Comparative Simulation of NASA’s Waterfall Process and Agile Process Using Innoslate Lifecycle Modeling Language,” explores using Innoslate to simulate and compare development methodologies for large-scale, safety-critical systems, specifically satellite systems.

Before diving into the study, here is a quick comparison of Agile and Waterfall.

What is the Agile Method?

Agile is a flexible, iterative approach to project management characterized by frequent collaboration, continuous feedback, and adaptability to change. 

Keep Learning about Agile Systems.

• A Guide to Agile Application Lifecycle Management (ALM)
• Agile Systems Engineering Using the Middle-Out Process

What is the Waterfall Method?

Waterfall is a linear, sequential method with distinct phases that must be completed in order, offering a structured and predictable path but limited flexibility once each phase begins.

MBSE for Satellite Systems

The study modeled the development of a fictional mid-size Low Earth Orbit (LEO) satellite using Innoslate’s Lifecycle Modeling Language (LML) diagrams to compare Agile vs Waterfall for space systems. Researchers created two complete models within Innoslate:

• One model used NASA’s traditional Waterfall process, based on SP-6105, progressing from Phase A (Concept Studies) to Phase D (Integration and Testing).
• Another model used a tailored Agile approach, enhanced with a Continuous Assurance Plugin (CAP) that incorporated automated compliance checks, hazard analysis, and traceability tools.

The project used Innoslate to build activity diagrams, simulate project timelines using Monte Carlo methods, estimate costs, and visualize system architecture. Thanks to Innoslate’s integrated modeling and simulation capabilities, the research team was able to perform an objective comparison of the two development models.

Key Findings in Both Agile and Waterfall MBSE

• The Agile approach, modeled and simulated in Innoslate, delivered the satellite in less than half the time (2.4 years) compared to the traditional Waterfall method (5.89 years).
• Labor costs were significantly reduced using Agile ($2.6M vs. $7.8M).
• Innoslate helped address the inherent challenges of applying Agile in regulated, safety-critical environments by enabling:
  
  
  • Continuous compliance tracking and verification.
  • Hazard and fault analysis via integrated MBSE features.
  • Robust traceability between requirements, actions, and test artifacts.

Why This Matters

This research demonstrates how Innoslate enables systems engineers to explore, evaluate, and validate various lifecycle strategies early on, not only in satellite development but also in numerous other projects. In regulated and complex fields like aerospace, being able to simulate both Waterfall and Agile approaches enables decision-makers to optimize for speed, cost, and compliance without risking system integrity or safety.

Try an Agile MBSE Approach for Critical Systems

Keep learning with the Agile MBSE Satellite System for Fire Detection Example. 

Explore how MBSE simulation works in Innoslate. Try it now.

Related Readings:

• Ultimate Guide to MBSE
• Navigating Defense and Aerospace Compliance with MBSE
• ROI of MBSE
• Systems Simulation With Innoslate's MBSE Tools Webinar