How a fifth-generation Edinburgh plumbing and heating business moved from two hundred pieces of paper on the floor to automated invoicing, family time back, and an AI-powered future.
Stuart Blackhall spent his entire childhood telling people he wanted nothing to do with the family business.
"Through my whole childhood, I told anyone that would listen that I didn't want to have anything to do with the family business. I left, I studied elsewhere, I went into sales roles in big companies, and even when I moved home, I still had no intention of getting involved."
He studied business and marketing in Leeds. He built a career in sales at BT and Nestlé Rowntree. He moved back to Edinburgh after about twelve years, still unsure what came next — but certain it wasn't plumbing and heating.
Then his mother collapsed in the office.
She had worked alongside Stuart's father in the business for more than twenty years. When she was admitted to hospital, the family needed someone to step in. Stuart said he'd help out for a few weeks. What he found when he walked through the door changed the next fifteen years of his life.
"On the day my mum was admitted to hospital, I said I'd come into the office to help out. I genuinely thought I was just helping for a few weeks. But when you step into a business your dad has run, that had put you through school, that had done all this — and I'd studied business and marketing, I'd worked in blue-chip sales companies — straight away I realised my dad didn't even have a website."
P. Blackhall Limited had been in the family for five generations. It was busy, well-regarded, and built on genuine craft. It was also built entirely on paper, memory, and the sustained effort of a small number of people who never really switched off.
Stuart saw it immediately. And he couldn't look away.
Two Hundred Pieces of Paper on the Floor
The picture Stuart walked into wasn't a broken business. It was a functioning one, held together by systems that worked because people made them work.
His father knew every live job without looking anything up. When a job came in, it went on the whiteboard. A file was made, put in the filing cabinet. The engineer went out with a paper sheet, handwrote the hours, materials, parking, and any notes, and brought it back to the office when the work was done.
"My dad's memory — pre-IT, pre-tech — he knew every single job that was going on."
For reactive jobs, that meant one sheet. For quoted jobs, it meant a thick ream of paper depending on how many engineers were on site and how many days the work ran. Either way, the paper eventually came back to the office, where it joined the pile.
And the pile was the problem.
About two hundred jobs a month. Two hundred pieces of paper that had to be physically sorted before a single invoice could go out. Every Saturday morning, Stuart and his father laid them out on the office floor — four or five square metres of paperwork, sorted into piles by job type — before the invoicing session could begin.
"We were putting two hundred bits of paper on the floor every Saturday before a four-to-six-hour invoicing session."
That was five to seven hours, every weekend, just to process work that had already been done. Cash flow moved at the speed of the paperwork. If the admin lagged, so did the money coming in. And if a customer rang for an update mid-week — Stuart still describes the experience with a kind of good-humoured retrospect.
"I've still got post-traumatic stress from a customer phoning up going, 'I'm customer A from address A looking for an update.' At that point, you'd just press hold on the phone, grab two hundred pieces of paper, and flick through until you found their record. And that was accepted. That was how we did it."
For Stuart — who had just come from a blue-chip sales environment where he was working on a handheld digital device — the gap was impossible to unsee. But he was careful about how he approached it.
"The people I was working with had built that business and got it to where it was. They were probably happy with how things were running. So change wasn't about saying it was wrong, it was about recognising it couldn't keep going the same way forever."
Paper-Free Isn't the Same as Problem-Free
The first move was the most obvious one: get off paper.
Stuart introduced an entry-level, cloud-based system. It wasn't BigChange, but more of a one-dimensional database with an app that let engineers send photos back to the office. Basic, but it was a start.
"We brought in an entry-level cloud system, and it helped in some ways. It digitised the paperwork, but it didn't change how the business actually worked. We realised pretty quickly that paper-free didn't automatically mean problem-free."
The forms moved onto a screen. The workflow didn't. Jobs were still processed as complete units — if one task was outstanding, the whole job waited. Invoicing still bottlenecked at the end of the process. Admin still stacked up. The system captured information but didn't change how work moved through the business.
The experience taught Stuart something more important than anything the software delivered.
"The big learning for me was that effort wasn't the issue. The structure was. We were holding entire jobs back from invoicing because one small thing wasn't finished, and that was killing cash flow."
A boiler service would be complete and ready to bill. But if the same job included a tap repair and the part hadn't arrived yet, the entire job stalled. The finished work waited for the unfinished work. Revenue sat idle. It wasn't a paperwork problem anymore — it was a structural one.
The Change That Put Everything in Perspective
The breakthrough came from looking at the jobs differently.
Stuart began breaking work into smaller, more clearly defined segments. Boiler services were treated separately from reactive repairs. Quoted works were split from add-on jobs. Instead of waiting for everything to be done, individual pieces of work could move through the business — and through invoicing — on their own timelines.
"Once we started breaking jobs down properly — boiler services, small reactive work, larger jobs — everything changed. You invoice what's done, not what's still waiting, and suddenly the business moves at a completely different pace."
It sounds simple, but for Stuart, the impact was revolutionary. Completed work could be billed immediately. Outstanding tasks no longer held unrelated work hostage. The office could see — at a glance — what was done, what was in progress, and what was ready to raise.
It was this structural thinking that led Stuart to BigChange. He wasn't looking for a system that would digitise his paperwork. He'd already learned that lesson. He was looking for a system that could support the way he now understood the business needed to work.
"The onboarding is daunting because you're putting faith into something that runs your business — and this is five generations of responsibility. I didn't even like the name BigChange at first. I didn't feel like I needed to be told that my business needed a big change. But five years in, I get it now."
In BigChange, Things Started to Click
The benefits of BigChange didn't arrive all at once. They came in stages — specific moments where a problem the business had lived with for years simply stopped happening.
One of the clearest examples was a complaint the office had fielded for as long as Stuart could remember: customers calling to say the engineer had only been on site for fifteen minutes.
For years, the team dealt with it reactively. Customer calls. The office investigates. Job card gets sent. Issue resolved, eventually. But the calls kept coming. Then Stuart changed the trigger.
"For years we got the complaint: 'The engineer was only there fifteen minutes.' We used to send job cards after the complaint. When we started sending them automatically, the phone calls stopped."
By sending job cards to every customer the moment work was completed — not just the ones who complained — the business made a whole category of friction disappear before it started. Customers had the information before they thought to ask for it. The complaints didn't need resolving because they didn't arise.
That pattern repeated across the operation. Automation didn't just make things faster, it made certain problems structurally impossible. Three or four calls a week, five to ten minutes each, eliminated. And as Stuart tested the approach further — eventually moving to automatically sending job reports, certificates, and invoices for completed thumbs-up jobs — the time savings compounded.
The BigChange customer success team played a significant role in unlocking this. Stuart keeps a running list of notes from their sessions — and references them months later. The in-person customer events at Murrayfield were equally formative: sitting at a table with other BigChange customers, trading solutions to problems they'd each already solved.
"At that table, we hashed out two problems. I gave them a solution, and they gave me a solution. The value of sitting with another business that runs BigChange is absolutely huge."
Business Impact and Beyond
When Stuart stepped into the business, Saturdays belonged to the office floor. Two hundred pieces of paper, sorted and invoiced, week after week, year after year. So much so that Stuart gained a new appreciation for what his father sacrificed when he was a kid, while embracing a new era for the business.
"My dad never came to watch me play rugby because he was invoicing on Saturdays. I coach my son's rugby team. I pick my kids up from school. I don't go into the office until ten."
That single contrast — a father missing the games, a son coaching the team — says more about what operational transformation actually means than any revenue figure. The business is still busy. The engineers are still working. But the time that was once consumed by paperwork, chasing information, and weekend admin is now spent differently.
Stuart's wife now works as the financial director, running the numbers from home while Stuart manages from the office or, increasingly, wherever he needs to be. Staff queries, van incidents, holiday requests — all of it goes through the BigChange app now. Engineers are redirected there by default. The managing director is no longer the first stop for every conversation.
"If someone's running around the office with a pen and a Post-it note, we've got a problem."
The revenue numbers reflect it too. When Stuart took on BigChange, the business was turning over around £800,000. It's sitting closer to £1.4 million now, with a clear target past £2 million. But the growth Stuart is most interested in isn't headcount: it's capacity.
What Comes Next
Now, the conversation has moved on from digitisation. Stuart is thinking about and implementing AI.
The foundations are in place: jobs segmented and structured correctly, automation running, information flowing freely. Now he wants to use that foundation to go further, specifically to take on the administrative load that still requires people to stop what they're doing and answer a phone.
"Office staff are hard to find, phones are disruptive, and admin tasks just keep growing. AI gives us a way to handle that without piling more pressure onto people. It's not about replacing the business — it's about making it workable."
His vision is specific. AI answering incoming calls. AI creating job records inside BigChange from those calls. Customers booking standard services — a commercial boiler service, for instance — through a chatbot, which creates the appointment, dispatches the engineer, and, when the job comes back thumbs-up, automatically sends the invoice and report. No human touchpoint required for the routine work. People freed up for the complex work.
"I want AI to do fifty percent of my business."
And now with the BigChange Lightning release, the path is clearer than it's ever been, because the business is structured in a way that makes it possible. The paper is gone. The workflows are defined. The jobs are segmented correctly. BigChange Lightning has something solid to build on.
Stuart's father built a business that lasted five generations on hard work, memory, and trust. Stuart inherited that foundation and spent fifteen years making it sustainable — changing not just the tools but the structure of how work moves through the business. Whatever comes next for P. Blackhall, it won't be built on memory and Saturday mornings. It'll be built on what Stuart put in place — and passed forward to the generation that comes after him.
"If you're a generational business still running on paper, you're making life harder than it needs to be. You don't have to lose what makes the business yours to change how it runs."
