Why we quote scope, not hours
Hourly billing prices effort and leaves the outcome unowned. Fixed-scope pricing moves estimating risk to the side that controls it, and forces both parties to define done before work starts.
Contents
We quote a defined scope at a fixed price because hourly billing prices effort and leaves the outcome unowned. Fixed scope moves estimating risk to the party that controls the estimate, and it forces both sides to write down what done means before any work starts.
Key takeaways
- Hourly billing prices time. The client carries unbounded cost risk, and the supplier earns more by working slower — an incentive nobody defends out loud.
- Scope creep is the shared failure mode. PMI's Pulse of the Profession 2017 found 51% of projects experienced scope creep and 62% finished within budget, across 3,234 practitioners surveyed.
- Requirements, not estimates, are the usual cause. PMI reported in 2014 that 47% of unsuccessful projects miss their goals because of inaccurate requirements management.
- Size makes it worse regardless of billing model. McKinsey and the University of Oxford found large IT projects ran 45% over budget and delivered 56% less value than predicted.
- A quote is only fixed if it names exclusions, review rounds, acceptance criteria and a priced change procedure. Everything else is a wish.
What hourly billing actually prices
An hourly rate prices attendance. It says what an hour of a named role costs and stays silent on what the hour produces. Two consequences follow, and both land on the client.
First, the total is unknowable until it has been spent, so the budget is a guess the client has to make. Second, efficiency reduces the supplier's revenue. That incentive is usually managed with goodwill, and goodwill isn't a control.
McKinsey and the University of Oxford studied more than 5,400 IT projects and found that large projects — those above $15 million USD — ran on average 45% over budget and 7% over schedule while delivering 56% less value than predicted. Around 17% overran budget by more than 200% (McKinsey & Company, October 2012).
Hourly billing doesn't cause those overruns. It just makes them invisible until the invoice arrives.
Scope creep is the failure mode both models share
Fixed pricing doesn't remove scope creep. It moves the moment of discovery forward, to the point where somebody has to say that a request sits outside the agreement.
The Project Management Institute's Pulse of the Profession 2017, based on a survey of 3,234 practitioners and published in February 2017, reported that 51% of projects experienced scope creep, 62% were completed within budget, and organizations wasted an average of $97 million USD for every $1 billion USD invested (PMI).
The useful question isn't who absorbs the overrun. It's who notices it first, and whether they're contractually obliged to say so.
What a fixed-scope quote must contain
A fixed price without a fixed definition is a trap for both sides. Six elements make the definition hold:
- Deliverables named individually, with format and quantity.
- Exclusions, written before the deliverables, because they're the part that gets argued about.
- Assumptions and dependencies, each with an owner and a date.
- Review rounds, counted, with a stated turnaround for feedback.
- Acceptance criteria that a third party could check without the team in the room.
- Payment milestones tied to deliverables rather than to calendar dates.
The site or system also has a life after launch, and the running cost of owning it belongs in the same conversation as the build price.
PMI's 2014 report on requirements management found that 47% of unsuccessful projects failed to meet their original goals because of inaccurate requirements management (Project Management Institute, August 2014).
Without acceptance criteria, "done" is an opinion, and opinions arrive after the invoice.
Change control is the part people skip
Change isn't the problem. Unpriced change is. A working procedure has three steps. The request goes in writing, it comes back with a price and a schedule impact, and no work starts until someone with authority approves it.
Harvard Business Review reported in September 2011 that Levi Strauss took a charge of $192.5 million USD against earnings after an SAP migration went wrong. That's the top of the distribution, not the median, but the mechanism is ordinary: requirements moved and nobody repriced them.
A change procedure is what keeps a fixed price honest. Without it, fixed price becomes a negotiation about memory.
When hourly is the honest answer
Three cases justify time and materials: genuine research where the question changes as you answer it, support retainers with unpredictable volume, and discovery, before there's enough information to scope anything. A cap per period plus a written report of hours keeps those arrangements measurable.
Our answer to the third case is to sell discovery as its own small fixed-price engagement that produces a written scope. The client owns a document they can take anywhere, which is also the fastest way out of a market that compares proposals on price alone.
FAQ
What happens if a fixed-scope project takes longer than we estimated?
We absorb it, provided the scope didn't change. That's the trade the client is paying for. If the scope did change, the change procedure applies and the work is repriced before it starts, not after it ships.
Doesn't fixed scope encourage a supplier to cut corners?
It would, if acceptance criteria were vague. Written criteria that a third party can verify remove the incentive, because work that fails them isn't delivered. Quality control belongs in the scope document, not in the relationship.
How many review rounds should a quote include?
Two on each deliverable is a workable default, with a stated turnaround for consolidated feedback. Unlimited rounds sound generous and produce the worst outcomes, because they remove any deadline for deciding.
Where to start
Write the exclusions first, then the acceptance criteria, then the price. A quote built in that order is harder to write and much harder to argue with later. If discovery is needed, sell it separately rather than guessing at a number to look competitive. Six months of quoting this way will show something an hourly rate never reveals: which projects were mis-scoped, and whether the fault was the estimate or the requirements underneath it.
