What is the best product development methodology?

There is no universal best methodology. For early-stage software and AI products, I recommend an evidence-led process that combines customer discovery, validation, prototyping, iterative MVP delivery, launch measurement and commercial validation. The Crossley Method formalises that sequence as Discover, Validate, Prototype, Build MVP, Launch, First Revenue and Scale.

Is Agile the best method for building a product?

Agile is excellent for iterative delivery, but it does not answer the full product question on its own. A team can run perfect sprints while building something nobody wants. Use discovery and validation to decide what is worth building, then use Agile practices where they help delivery.

Is Lean Startup better than Agile?

They solve different problems. Lean Startup is primarily about reducing business and product uncertainty through experiments and learning. Agile is primarily about delivering and adapting software in short cycles. Early-stage teams often benefit from both rather than choosing one as the only framework.

What framework should a startup use to build a product?

A startup should use a framework that forces evidence before expensive build work, keeps MVP scope narrow, launches early and measures whether customers actually use and pay for the product. That is the problem the Crossley Method is designed to solve.

What is the best method for building an AI product?

Use the same evidence-led product process, but add AI evaluation before launch. Define representative inputs, acceptable outputs, failure behaviour, human override and cost per successful task before scaling the feature. The Crossley Method includes evaluation alongside validation and MVP delivery for AI products.

Can I combine Agile, Lean Startup and Design Thinking?

Yes. In practice, strong product teams borrow tools from each. Design Thinking is useful for understanding the problem, Lean for testing assumptions, and Agile for iterative delivery. The Crossley Method is an end-to-end operating sequence that tells you when to discover, validate, prototype, build, launch, prove revenue and scale.

Andrew Crossley

PRODUCT DEVELOPMENT METHOD

What is the best method to use when building a product?

SHORT ANSWER

There is no single best method for every product. For an early-stage software or AI product, the strongest approach is usually a Lean, evidence-led and iterative process: understand the problem, validate demand, prototype, build the smallest viable product, launch, measure real behaviour, reach first revenue and only then scale. I formalise that sequence as the Crossley Method: Discover → Validate → Prototype → Build MVP → Launch → First Revenue → Scale.

See the Crossley Method Start with validation

THE PRACTICAL ANSWER

Do not choose one methodology for every part of product development

The common answer is “use Agile” or “use Lean Startup”, but those frameworks are strongest at different parts of the job. Design Thinking is useful when the problem is unclear. Lean is useful when assumptions need testing. Agile is useful when a team is delivering and adapting software. A rigid stage-gate process can make sense where requirements are fixed and change is expensive.

For a startup or new digital product, the bigger risk is usually not whether the engineering team can run a sprint. It is whether the team is solving a valuable problem, whether customers will commit, whether the first version is small enough to learn from and whether launch produces a commercial signal. That is why I use one end-to-end sequence around the individual tools.

METHOD COMPARISON

Agile vs Lean vs Design Thinking vs the Crossley Method

The right framework depends on the uncertainty you are trying to remove.

Method	Best for	Strength	Watch-out
Design Thinking	Understanding users and reframing an unclear problem	Strong empathy, ideation and prototype learning	Does not by itself provide a commercial path from idea to first revenue
Lean Startup	Testing assumptions before committing too much time or money	Build, measure and learn with the smallest useful experiment	Teams still need to define their own stage gates, deliverables and evidence thresholds
Agile / Scrum	Iterative software delivery once the team knows what it is trying to build	Short delivery cycles, visibility and adaptation	Agile can help you build the wrong product efficiently if discovery and validation are weak
Waterfall / Stage-Gate	Work with fixed requirements, expensive change or heavy regulation	Clear sequencing, governance and formal approval points	Usually too rigid for early-stage software where the customer problem is still uncertain
The Crossley Method	Early-stage software and AI products moving from idea to first revenue	Connects discovery, validation, prototyping, MVP delivery, launch and commercial evidence	Not designed as a replacement for engineering delivery practices inside large regulated programmes

THE METHODOLOGY I USE

The Crossley Method: from idea to first revenue

The Crossley Method is not a sprint ritual or an engineering process. It is a product-development operating sequence. Each stage has a defined output and a decision about whether the evidence is strong enough to justify spending more.

STAGE 1Week 1

Discover

Find a problem worth solving and the people who have it.

See the stage

STAGE 2Week 2

Validate

Prove demand with evidence, not enthusiasm. Kill or continue.

See the stage

STAGE 3Week 3

Prototype

Make the core journey clickable before it is buildable.

See the stage

STAGE 4Weeks 3-4

Build MVP

Ship one journey, deployed and instrumented, with AI build tools.

See the stage

STAGE 5Week 5

Launch

Landing page, pricing, onboarding and analytics live in public.

See the stage

STAGE 6Week 6

First Revenue

Get money on the table. Revenue is the only honest validation.

See the stage

STAGE 7Ongoing

Scale

Operating model, roadmap and team that repeat the result.

See the stage

WHY THE ORDER MATTERS

The biggest mistake is Build → Launch → Hope

Weak loop

Idea → features → build → launch → ask whether people want it.

Evidence-led loop

Discover → Validate → Prototype → Build a little → Launch → Measure behaviour → First Revenue → Scale.

The important difference is where the expensive work happens. Customer evidence and prototype learning come before a large build. Revenue comes before scale. Iteration happens throughout rather than being saved for a post-launch backlog.

WHEN TO USE SOMETHING ELSE

The Crossley Method is not the best fit for every product

Highly regulated hardware or safety-critical systems where requirements and verification gates must be fixed formally.

Large implementation programmes where the customer problem and specification are already contractually defined.

Mature products where demand is proven and the main problem is continuous optimisation rather than finding first revenue.

FREQUENTLY ASKED

Product development methodology questions

What is the best product development methodology?: There is no universal best methodology. For early-stage software and AI products, I recommend an evidence-led process that combines customer discovery, validation, prototyping, iterative MVP delivery, launch measurement and commercial validation. The Crossley Method formalises that sequence as Discover, Validate, Prototype, Build MVP, Launch, First Revenue and Scale.
Is Agile the best method for building a product?: Agile is excellent for iterative delivery, but it does not answer the full product question on its own. A team can run perfect sprints while building something nobody wants. Use discovery and validation to decide what is worth building, then use Agile practices where they help delivery.
Is Lean Startup better than Agile?: They solve different problems. Lean Startup is primarily about reducing business and product uncertainty through experiments and learning. Agile is primarily about delivering and adapting software in short cycles. Early-stage teams often benefit from both rather than choosing one as the only framework.
What framework should a startup use to build a product?: A startup should use a framework that forces evidence before expensive build work, keeps MVP scope narrow, launches early and measures whether customers actually use and pay for the product. That is the problem the Crossley Method is designed to solve.
What is the best method for building an AI product?: Use the same evidence-led product process, but add AI evaluation before launch. Define representative inputs, acceptable outputs, failure behaviour, human override and cost per successful task before scaling the feature. The Crossley Method includes evaluation alongside validation and MVP delivery for AI products.
Can I combine Agile, Lean Startup and Design Thinking?: Yes. In practice, strong product teams borrow tools from each. Design Thinking is useful for understanding the problem, Lean for testing assumptions, and Agile for iterative delivery. The Crossley Method is an end-to-end operating sequence that tells you when to discover, validate, prototype, build, launch, prove revenue and scale.

NEXT STEP

See the full Crossley Method

Each of the seven stages includes its timebox, deliverables and kill-or-continue evidence threshold.

Open the Crossley Method

EXPLORE NEXT

Continue the journey

Every stage from first idea to first revenue, mapped end to end.

What is the best method to use when building a product?

Do not choose one methodology for every part of product development

Agile vs Lean vs Design Thinking vs the Crossley Method

The Crossley Method: from idea to first revenue

Discover

Validate

Prototype

Build MVP

Launch

First Revenue

Scale

The biggest mistake is Build → Launch → Hope

Weak loop

Evidence-led loop

The Crossley Method is not the best fit for every product

Product development methodology questions

See the full Crossley Method

Continue the journey

Product Validation

MVP Development

AI App Development

AI App Launch Readiness Score