About Optimum Assessment

Encourage growth

We believe in the power of assessment and certification as the engine for personal and professional growth. With innovative and digital tools, we enable people and organizations to excel by making knowledge and talents transparent and valued.

Our mission

Creating in partnership with our customers the ultimate assessment experience, anytime, anywhere.


Partner in digital assessment

We see our clients as partners with whom we work on a project or structural basis to create the ultimate assessment experience. Optimum Assessment not only devises solutions, we also provide implementation and expert guidance and support. We unburden where necessary. Our concrete and practical approach has already allowed many clients to excel in the new digital landscape. Together, we are taking digital testing to the next level.

Optimum Assessment - your partner in digital assessment


Optimum Assessment Platform

Optimum Assessment Platform is Optimum Assessment’s innovative digital testing platform. Thanks to state-of-the-art technology, Optimum Assessment Platform is not only safe and reliable, the software is also fully interactive. With 9 advanced modules, you can easily design, host, monitor and analyze assessments.

Solid partner base

Our robust, reliable and above all secure assessment system supports formative, summative and practice-based testing. This makes Optimum Assessment Platform broadly applicable. Thus, for many years our assessment software has supported large (national) examination systems on the one hand and smaller professional certifications on the other. In addition, Optimum Assessment serves clients in areas as diverse as government, examination institutions, industries & professional associations, private and funded education. We are proud of our partners and actively invest in the relationship. See a list of our partners here.


Ever since 1990, Optimum Assessment (until recently Citrus Andriessen) has distinguished itself with excellent technology and high-quality knowledge in the field of digital assessment, examination and certification. As a founder in digital assessment, we launched the first SaaS solution on the Dutch testing market some 30 years ago. A robust, secure and user-friendly assessment environment with over one million users per year. Meanwhile, we support the assessment domain with the modular and highly innovative Optimum Assessment Platform.

Citrus Andriessen

Optimum Assessment is a trade name of Citrus Andriessen. Citrus Andriessen has been an established name in the Dutch reviewing world for decades. Demand for our product and service offerings is now growing beyond our borders. Realizing international growth ambitions, requires a recognizable and unambiguous international name. Citrus Andriessen will thus continue under the name Optimum Assessment as of 2023.

Working at Optimum Assessment?

What Optimum Assessment is all about is creating an innovative, reliable and high-quality assessment solution: Optimum Assessment Platform. We have an international outlook, an innovative attitude and we go for a personal click with our client. This is how we achieve the optimal assessment experience, anytime, anywhere.


Why Optimum Assessment?


Your partner in digital assessment

Excellent service & support


Carefree examinations anytime, anywhere

Innovative, user-friendly and secure assessment software


Committed and inspired professionals

Top-notch key experts & developers



Always the solution that suits you


Want to know more?

Want to know more about our organization or services?