Design and Development of a Digital RAM Tool for AUVs

Abstract

Title: Design and Development of a Digital RAM Tool for AUVs

Authors: Oscar Cedell and Jacob Persson

Supervisors: Johan Marklund (LTH), Gustav Rehnborg (Saab Naval), and
Niklas Blomgren (Saab Naval)

Problem description: Autonomous underwater vehicles (AUVs) are longlife, mission-critical systems for which life cycle cost is strongly affected by
Reliability, Availability, and Maintainability (RAM). In industrial practice,
RAM-related analyses are used to support decisions regarding design, maintenance planning, life extension, and phase-out. Such analyses require systematic collection, structuring, and follow-up of operational and maintenance data over time, often through Failure Reporting, Analysis and Corrective Action System (FRACAS)-related practices and other structured support systems. Saab Naval currently lacks a coherent digital RAM tool adapted to AUVs and their operational availability. Existing commercial alternatives are difficult to apply in this context due to security-classified, export-controlled, and customer-sensitive data, which creates a need for a tailored solution that can operate within secure IT environments.

Purpose: The purpose of the thesis is to develop a digital RAM tool tailored
for AUVs. The tool will be based on an analysis of how in-service data feedback
can be collected, structured, and presented to support evaluation of RAM.

Method: The study follows a structured development lifecycle, beginning with
a requirements elicitation phase informed by a literature review, stakeholder
interviews, and benchmarking. These findings serve as the foundation for
subsequent requirements engineering and software development. The literature
review establishes the theoretical foundation through RAM theory, FRACAS,
reliability growth, Integrated Logistics Support (ILS), life cycle management,
and the S5000F in-service data feedback specification. Stakeholder input is collected through semi-structured interviews and continuous dialogue with
relevant stakeholders at Saab Naval, including RAM/ILS experts and potential
users involved in both data input and analytical use of RAM analyses. The
findings are compiled into a product requirements document containing both
functional and non-functional requirements, which then guides the design
and development of the digital tool. The resulting solution is developed as a
web-based application intended for handover and further instantiation within
Saab Naval’s secure IT environment.

Conclusions: The thesis shows that a structured digital RAM tool tailored for
AUVs can be developed by combining established RAM/FRACAS methodology with a pragmatic interpretation of S5000F and the constraints of a
secure organisational environment. The web-based tool that was developed
demonstrates how problem reporting can be structured and reused to support
RAM-related follow-up over time. The work also indicates that long-term value
depends on more than the implemented software and calculations. Consistent
reporting practices, clear roles and access control, and sustained data quality
management are required for the tool to become effective for decision-support.
Full validation of the benefits remains dependent on deployment and integration
within Saab Naval’s secure IT environment and evaluation in live operations.

Contribution: This thesis contributes a structured and documented approach
to applying RAM in AUVs. It also contributes with an analysis of how
established RAM methods and standards can be adapted to a security-critical
industrial context, and with practical experience from developing a digital
decision-support tool for use in secure IT environments.

Popular Abstract

This thesis develops a secure digital tool that helps Saab Naval collect, structure, and analyse reliability, availability and maintenance data from autonomous underwater vehicles, supporting better decisions on maintenance, long-term performance, system lifetime, and life-cycle cost.

• author: Persson, Jacob and Cedell, Oscar
• supervisor: Johan Marklund
• organization: Department of Industrial and Mechanical Sciences; Production Management
• course: MIOM05 20261
• year: 2026
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Reliability, Availability, Maintainability, RAM, FRACAS, Autonomous Underwater Vehicles, AUV, S5000F
• other publication id: 26/5333
• language: English
• id: 9229271
• date added to LUP: 2026-06-02 16:20:36
• date last changed: 2026-06-02 16:20:36