A book in the making. Ideas for your next challenge.

We have achallenge.

A Field Guide for Solving Problems in Challenging Times

Why we’re writing this book

Gijs Verrest and Jens Refflinghaus, the authors of We Have a Challenge
The people behind the bookGijs Verrest
Jens Refflinghaus
Solving Forces

Firefighting. Recurring problems. Ad-hoc actions. We see our clients navigating high complexity, price wars, cost and competitive pressure, volatile markets and uncertain supply chains.

That’s why we’re writing this book: a practical guide to finding clarity, solving problems together and steering towards calmer waters in challenging times.

Cover concept for We Have a Challenge by Gijs Verrest and Jens Refflinghaus
Our book cover concept · The book is in development.

A field manual for real-world challenges.

For the moments when a team needs to understand what’s happening, find a way forward and turn a decision into action. We’re bringing practical questions, tools and stories together in one book.

Follow its journey from working manuscript to finished book — and take useful ideas into your own work along the way.

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Which challenges do you recognise?

What keeps pulling us back into urgent fixes?

The people behind the book

For real-world practice.

We’re Gijs and Jens: solution designers, facilitators and trainers. We see the whole picture of problem solving — from the first question to effective implementation.

Together, we bring more than 45 years of delivering results through problem solving. We work across all industries and bring that experience together in this book: a practical guide to tackling challenges together.

Gijs Verrest

Solution designer, facilitator & trainer · Netherlands

Jens Refflinghaus

Solution designer, facilitator & trainer · Germany

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Before you join

A few things worth knowing.

What exactly will I receive?

An email every two weeks with practical insights, selected insights from the manuscript and updates on the book’s development. We’ll also let you know when the book is published and where to find it.

Is the book available yet?

The book is in development. There is no publication date announced on this page. Join the insights to follow its progress and hear when it is ready.

Which language will the emails be in?

Use EN, DE or NL at the top of this page to choose the language for your subscription. You can review your choice just above the email field.

Can I leave the list?

Yes. The insights are free, and every email will contain an unsubscribe link. Signing up does not commit you to buying the book.

Your next challenge won’t wait for the book.

Follow the writing. Take a useful idea into your next conversation.

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Privacy notice

Last updated: 20 September 2026

1. Who we are

This website and its newsletter are run jointly by two independent businesses:

Jens Refflinghaus – Solving Forces Germany, Hagener Straße 224, 44229 Dortmund, Germany · jens.refflinghaus@solvingforces.de
Gijs Verrest – Solving Forces Netherlands, Vlietsingel 8, 3831 SV Leusden, Netherlands · gijs@solvingforces.com

We decide together how the newsletter is run and are joint controllers for it (Art. 26 GDPR). Jens manages the newsletter account; Gijs manages the website and domain. You can contact either of us with any privacy question, and we will coordinate the answer.

2. Visiting this website

The website is hosted on GitHub Pages (GitHub, Inc., USA). When you visit, GitHub processes your IP address and basic request data to deliver the page and keep its service secure. GitHub is responsible for these logs itself; see the GitHub Privacy Statement. Our legal basis is our legitimate interest in running a secure website (Art. 6(1)(f) GDPR). We do not use analytics, advertising cookies or tracking tools on this website.

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If you sign up, we process your email address, your chosen language and a record of your consent (when you signed up and confirmed, which form you used, and your IP address). We use this to send you practical insights, book news and, later, offers for the book, roughly every two weeks. We only send the newsletter with your consent (Art. 6(1)(a) GDPR), which you confirm through a link in a confirmation email (double opt-in). You can unsubscribe at any time through the link in every email.

We do not track whether you open our emails. We do record which links you click, to see which topics are useful. This is part of your newsletter consent; unsubscribing stops it.

We use MailerLite (MailerLite Limited, Dublin, Ireland) to run the sign-up forms and send the newsletter. MailerLite acts on our behalf under a data processing agreement and stores subscriber data in the EU. The sign-up form is loaded from MailerLite when you open this page, so MailerLite receives your IP address even if you don’t sign up.

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Only the two of us and the service providers named above. We never sell your data or share it for other companies’ advertising. Some providers may access data from outside the EU; such transfers are protected by the EU-US Data Privacy Framework or EU Standard Contractual Clauses.

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Unconfirmed sign-ups are deleted after 14 days. Subscriber data is kept until you unsubscribe. After that, we keep your email address on a block list so you are not added again, and your consent record for up to three years so we can prove you consented. Emails are deleted when no longer needed, unless the law requires us to keep them.

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You have the right to access, correct or delete your data, to restrict its processing and to receive it in a portable format. You can object to processing based on legitimate interest and withdraw consent at any time; this does not affect processing before the withdrawal. You can also complain to a data protection authority, for example the Autoriteit Persoonsgegevens (Netherlands) or the LDI NRW (Germany).

8. Changes

We will update this notice if our services or the law change.