The People Who Make the Difference
Portamus GmbH was founded as a spin-off of the University of St. Gallen (HSG). We think with structure and pragmatism: consulting should help, not impress. That means bringing your team along and adapting our approach to your reality, and delivering results that make a genuine difference. We operate with confidence at every level, from the business unit to the boardroom.
From HSG to the Heart of German Enterprise
Portamus was born at the University of St. Gallen (HSG), one of Europe's leading institutions for Enterprise Architecture. Our founding team brought together experienced enterprise practitioners with HSG's methodological rigour, united by a shared conviction: that the gap between business strategy and IT execution is the single biggest drag on organisational performance — and that closing it requires relentlessly practice-oriented consulting.
"Today, Portamus operates at the intersection of Enterprise Architecture Management, Business Process Management, and IT Service Management, deploying certified architects and experienced professionals who work directly with your senior teams."
Dr. Marcel Rosenberger, Managing Director, Portamus GmbH
Architects and Consultants Network
Every client engagement is led by a credentialed senior professional — not delegated to junior staff. Here are the people you can trust.
Dr. Marcel Rosenberger
Managing Director
Marcel founded Portamus as an HSG spin‑off and has since led enterprise architecture and process‑management engagements for large enterprises and public administrations across Germany and Europe. As interim Chief Architect, he oversaw the consolidation of Singapore’s government data centres, which host critical health‑sector infrastructure. He holds a doctorate in information systems and has published extensively on software migration, enterprise modelling, and social‑CRM architecture.
Sarah Rosenberger
Senior Financial Advisory
Sarah has extensive experience in financial consulting and the banking sector. At Portamus, she leads the demanding international client relationship management function. Her combination of financial expertise and many years of consulting experience ensures strong governance across all client projects. In addition, she runs her own financial services agency.
Dr. Olaf-Rüdiger Hasse
Senior Advisory Network
Olaf has decades of IT leadership experience and has held Senior Vice President and executive board positions at leading consulting and software companies. In these roles, he was responsible for operational management, growth strategy, and C‑level engagements at an international level. As a PhD physicist, he brings deep expertise in technology consulting, product strategy and development, and enterprise architecture management, and has extensive experience in leading global transformation programs.
Dr. Gerd Kopetsch
Senior Advisory Network
Gerd holds a degree in economics and has deep expertise in process design and organisational development. He channels this knowledge into coaching engagements and structured qualification programmes, helping organisations build internal capability alongside structural change. As Senior Advisor, he contributes expertise in change facilitation and process-driven organisational transformation in challenging business environments.
What Sets Our Approach Apart
Our clients return engagement after engagement because we take time to understand their organisation — and we deliver results, not just documentation.
HSG Foundation & Practical Impact
As a spin-off of HSG — one of Europe's leading institutions for Enterprise Architecture — we combine methodological rigour with a relentless focus on practical impact. Structured thinking, proven in your reality.
Certified Senior Expertise
TOGAF®, ITIL®, and SAP certified. We know these frameworks deeply — which is exactly why we know when to adapt them to your situation rather than follow them rigidly.
Vendor-Neutral
We advise independently of any technology vendor. Our recommendations are driven by your business needs alone.
Senior-Only Delivery
No junior consultants, no subcontracting. Every client works directly with our senior architects and analysts.
From Business Unit to Boardroom
We communicate on equal footing across every level and translate between the business, IT, and executive leadership — right up to the board. Stakeholder management is one of our core disciplines.
Measurable Outcomes
We define success metrics at the start and track them throughout — cost savings, process efficiency, delivery timelines.
Methodological Foundation — a Tool, Not an End in Itself
Our consultants hold the leading enterprise architecture and IT management certifications — so you know the frameworks are in safe hands, and won't be applied blindly.
TOGAF®
Certified
ITIL®
Foundation
SAP ERP
Certified
ArchiMate®
Foundation
ArchiMate®
Practitioner
ERP
TERP10
ADOIT
Trained
Solutions Business Manager (SBM)
Certified
Universität St.Gallen (HSG)
Spin-Off
Consulting Club
Premium Member
The Portamus Approach
Every engagement starts with listening. The methodology adapts to your organisation — your culture, your people, your pace.
Understand
We begin by comprehensively grasping your current state: business goals, IT landscape, stakeholder expectations, and pain points.
Analyse
We examine your architecture and processes in depth — assessing initiatives, tracking objectives, and identifying gaps.
Design
We develop architecture blueprints, process models, and transformation roadmaps aligned with your strategic direction.
Realise
We translate designs into implementation, working alongside your teams to ensure tangible, measurable outcomes.
Govern
We establish governance frameworks to sustain the architecture and ensure continuous alignment as your organisation evolves.
Ready to Discuss Your Enterprise Architecture Challenge?
Get in touch with our senior architects and consultants. We offer an initial discovery session to understand your situation before recommending a path forward.
Office hours Mon–Fri 9am–6pm CET.