Agile Fixed-Price Projects: Keep Scope Flexible, Secure the Budget

An agile fixed-price project fixes the budget and the time frame and keeps the scope flexible, so that the client caps its costs and can still respond to what the project teaches. Five contract models are common, and they differ in how they distribute risk. Which one fits depends on the uncertainty of the initiative, the trust between the parties and the possibility of stopping early.

The contradiction seems unresolvable. Procurement demands a fixed price because it needs a figure for the budget, and the business team demands agility because requirements change along the way. Both demands are legitimate, and both can be met once you know what may be fixed and what may move. This article shows the construction, compares the contract models and provides a calculation for the budget. It gives an overview and does not constitute legal advice: contract drafting in an individual case belongs with specialist lawyers.

Why do classic fixed-price projects often fail?

Classic fixed-price projects often fail because they fix scope, date and price at the same moment, before the initiative is understood. Project management knows this as a triangle of scope, time and cost. When all three sides are fixed, there is no room for new insight. Every change becomes a change request, and the supplier builds risks into the price that the client pays whether or not they materialise. At the other end, the supplier economises on quality, because scope is fixed and time is short.

The Agile Manifesto of 2001 sharpened the situation by placing customer collaboration above contract negotiation. The 2020 Scrum Guide describes sprints as a time box with a fixed frame and flexible content. The consequence for contracts is a shift: time and budget are fixed, and scope is movable and follows the greatest benefit for the client. How dates are kept within such a frame is described in the article on release planning.

Which contract models exist for agile projects?

Five models are common: a fixed price per iteration, a budget frame with options, a fixed price with a change budget, a time-and-materials contract with a cap, and a fixed price with an early exit. All five divide the risk differently, and none is right for every initiative.

The fifth model is known as “Money for Nothing, Change for Free” and goes back to Jeff Sutherland, a co-founder of Scrum. The idea behind it: the client may end the project early once the most valuable part of the scope has been delivered, and pays the supplier an agreed share of the remaining budget, which is 20 per cent in the Scrum Inc. template. Changes to scope remain free as long as they replace scope of equal effort. The supplier thus has an incentive to deliver value early, and the client saves money if less is needed than planned.

How do you calculate the budget for an agile fixed-price project?

You calculate the budget from the team's cost per sprint, the number of sprints and a reserve for the unforeseen. The example is illustrative. A team of five costs 25,000 euros per two-week sprint including overheads. For an initiative of sixteen sprints, the core budget is 400,000 euros. A reserve of 15 per cent raises the frame budget to 460,000 euros, which the client draws on only after a decision. The first two sprints serve to clarify matters, after which a reliable estimate of capacity exists and the parties decide whether to continue.

With an exit model, the share the client pays on early ending is also fixed. With a share of 20 per cent and an end after twelve sprints, the final payment is 20 per cent of the four remaining sprints, which is 20,000 euros, and the client saves 80,000 euros against the planned course. The example shows why the exit aligns interests: both sides gain when the benefit arrives early.

Which model suits which initiative?

The model follows three criteria: the uncertainty of the initiative, the trust between the parties and whether the benefit becomes measurable early. With high uncertainty and good trust, the fixed price per iteration fits, because the scope is chosen afresh each sprint. With clearly separable phases, such as design, build and operation, the budget frame with options fits, because the client decides anew at each boundary. With a clear core and few open points, the fixed price with a change budget fits, because the supplier can calculate the core with confidence.

Agile fixed-price models are unsuitable where the client provides no decision-making capacity within the project. A product owner who does not decide on priorities promptly turns every model into a schedule risk. The precondition is therefore a person on the client side who sets priorities, and a supplier who gives transparency on progress and capacity. The fundamentals of the method are covered in the article on Scrum in mid-sized companies.

How do you prevent disputes about scope?

You prevent disputes about scope through a shared definition of done and a visible backlog. The parties agree before the start on the criteria by which a result is accepted, and check them at the end of each sprint in a joint demonstration. The backlog, which the client can view, shows at any time what is planned, started and finished. Anyone who looks at the same criteria together at every acceptance avoids the late settling of accounts at the end of the project.

A second lever is dependencies. If the supplier waits for inputs from the client, such as access or business decisions, the project is delayed through no fault of the supplier. The agreement therefore names duties to cooperate with response times. The view in the article on dependencies between teams helps here and can be transferred to client and supplier. For initiatives with a fixed time budget, Shape Up offers a model that fits the scope to the time available.

Steering agile initiatives with Niehues Consulting

Niehues Consulting is a consultancy for AI management and organisation design from a delivery perspective, based in Düsseldorf. Founder Marin Niehues builds organisations that deliver, on projects ranging from VC-funded scale-ups to DAX 40 groups and in more than 20 countries on six continents. In the service line delivery management and organisation design he works as delivery manager, project manager or product owner, the roles that hold the budget, scope and delivery of an initiative together.

The approach follows the Niehues Delivery Model with three phases. Two test questions count for agile initiatives with a limited budget: which business outcome should change measurably? Who decides, who delivers, who uses? Once both are answered, scope and priority can be steered without losing sight of the budget. The scope and terms of an engagement are discussed in the free initial consultation of 30 minutes, which you can arrange via the contact form.