Print a purchase contract, put it on a desk, have it signed, scan it and email it to the subcontractor. Then wait and see whether it comes back signed. That is how it worked for a long time at installation company A. de Jong. Now the contract goes out from InstallWorks, the ERP package by BouwInfosys. Colleagues give their internal approval first, then the subcontractor signs digitally with ValidSign, often simply on their phone. "Everyone has their email on their mobile. You open it, you approve, done."
About A. de Jong and Hakim
A. de Jong is a family business headquartered in Schiedam, the Netherlands. Its installation engineering division builds installations for hospitals, schools and large companies, among others. The company also has an electrical engineering division and an energy division. The latter builds burners for refineries and works abroad a great deal. The company has more than 250 employees and has worked with BouwInfosys software for over twenty years.
Hakim Er-Rahhali joined A. de Jong in mid-2025 as information analyst and application manager. He is responsible for InstallWorks, which runs almost all of the company's processes. Digital signing was not new to him: he had already worked with it at his previous employer. He deliberately introduces change at a calm pace. "I am not one for the big bang. Step by step."
Showing how it used to be
In 2025, A. de Jong wanted contracts to be signed digitally and stored directly in the file in InstallWorks. Hakim knows how people react to a plan like that. "With every change you see a group of people from the business pushing back and asking: why this, why that?"
He did not win them over with a story about the future. He laid out the way of working at that moment, for management and the key users. "Print the contract and put it on the desk of the person who has to sign it. Then scan it and send it to the supplier." Whether the other party had actually signed the document afterwards was never checked. Anyone who said the new process was a lot of work got to see the old one right next to it.
A family business runs largely on trust, Hakim says. "But the goal is to grow, to work professionally and to cover yourself legally. Those were all arguments that made them say: we don't want to do it like this anymore."
From paper to digital
Before
- Create the purchase contract in InstallWorks
- Print and check the contract
- After approval: sign, scan and email
- Subcontractor prints, signs, scans and emails the contract
- Store the signed contract manually in the right file
- Create the purchase contract in InstallWorks
- Approve the contract in InstallWorks
- After approval: send digitally via ValidSign
- Subcontractor signs digitally via ValidSign
- Signed contract lands automatically in the right file in InstallWorks
Together with BouwInfosys
The integration between BouwInfosys and ValidSign already existed. Hakim saw it in action at the BouwInfosys customer day. "I got a twenty-minute, half-hour presentation of what it looks like. Then I said: this is what we need."
Things moved quickly after that. BouwInfosys heard through its own project manager that A. de Jong wanted to work with ValidSign. A phone call followed shortly after, and a week later an appointment was in the calendar.
Hakim did the initial setup together with the BouwInfosys consultant. "I wanted to know what was going on." They ran through scenarios in a test environment: an order, a purchase contract, the internal approval. Hakim speaks highly of the consultant. "He is very flexible, also when it comes to time." Questions that could not be answered on the spot, such as creating users in the ValidSign portal, were picked up shortly after the meeting.
When moving to production, Hakim noticed extra steps that he had not seen in the test. Together with BouwInfosys and ValidSign he traced the cause: the API settings in production were different from the test. "The solution is usually to get everyone around the table. In the end it was something very simple."
He took three weeks for the go-live: informing suppliers, informing colleagues, writing a procedure. He is down-to-earth about that last part. "You can document all you want, nobody reads it." So for the first few weeks he sat next to the colleagues who needed it.
Internal approval first, then the signature
For those who create a purchase contract, little has changed: it is still a document in InstallWorks that records the specific agreements with subcontractors. What is new is what happens next. Colleagues give their internal approval first. Then the contract goes to the subcontractor via ValidSign.
Project managers cannot proceed until the contract is signed. A dashboard shows which purchase contracts are still open, and it does more than inform. "That is a psychological effect you create," Hakim explains. Nobody wants their list to grow. Six months after go-live, he says, contracts are signed faster, almost without anyone noticing. "People are on board. There is even a demand to use ValidSign for more."
The next document
After the purchase contracts come the quotations. There, A. de Jong deliberately signs last: the customer first, then internally. Then come the maintenance contracts, and there is an idea for onboarding new creditors and debtors.
Hakim contributes ideas for the package along the way. He set up a key-user organisation with people from different disciplines, and this year several colleagues are going to the BouwInfosys customer day. "We put forward a lot of wishes and see that certain things get picked up. I like that." BouwInfosys keeps building too: the new version lets you send and configure reminders.
Hakim is in no hurry. "In the beginning everyone had all kinds of plans. I said: start simple, start at the beginning, let it prove itself and then we move on to the next thing."
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