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Stage-Gate and Agile Development: Debunking the Myths

Robert G. Cooper


A few months ago, I facilitated a heated meeting between software and hardware developers in a large U.S. firm, where the question was: for software development, whether Agile development and Stage-Gate can or should be used together (are they complementary?) or instead of each other (are they mutually exclusive?). This firm uses Stage-Gate very successfully for the development of its physical products; but some software developers are arguing that Agile, not Stage-Gate, should be used for software developments. During a recent trip to Europe, the same question arose in a major telecommunications firm, but they seemed to have resolved the issue, and in a positive way.

A second and related question concerns whether hardware developers can or should employ aspects of Agile development (for example, the notion of sprints). Both questions are particularly relevant when the firm’s development efforts include both hardware and software, and where the two must be integrated.

The Role of Agile Within Stage-Gate for Software Development

Stage-Gate and Agile are not substitutes for each other. Rather Agile is a useful micro-planning or project management method that can be used within Stage-Gate to accelerate certain stages.

Stage-Gate has long been popular as a method for driving new products to market, but it is not a project management or micro-planning model per se. Rather Stage-Gate is a comprehensive and holistic idea-to-launch system and a macro-planning process (Figure 1). It is cross-functional (i.e. involves technical product developers, but also Marketing, Sales and Operations). It is also an investment decision model (or a Go/Kill decision system), where the gates pose two vital questions: Are you doing the right project? And are you doing the project right?

By contrast, Agile development is designed specifically for product developers as a way to rapidly develop the working software (see box insert below). In practice, the Development Stage consists of a number of sprints, where each sprint or iteration produces a working product (executable code or software that works) that can be demonstrated to stakeholders (i.e. customers). An iteration may not add enough functionality to warrant a market release, but the goal is to have a potentially available release at the end of each iteration. Multiple iterations are usually required to release a product or new features; a sprint typically lasts 3-5 weeks.

Agile software development is a group of software and development methodologies based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizating, cross-functional teams. It promotes adaptive planning, evolutionary development and delivery, and time-boxed iterative approach, and encourages rapid and flexible response to change. It is a conceptual framework that promotes foreseen interactions throughout the development cycle. The Agile Manifesto introduced the term in 2001.

Thus Agile is a micro-planning or project management tool designed for writing software code and get to a working end-product quickly. Agile is best used during the Development and Testing Stages of a new-product project – that is, for two (Stages 3 and 4) of the five or six stages of the Stage-Gate model in Figure 1 – but not for the entire project from end-to-end. Furthermore, it is principally used by the technical, IT or engineering people developing the software code –  for example, it would not make much sense to have the Marketing or Operations facets of new product projects undertaken using an Agile approach. Table 1 summarizes some of the differences between Agile and Stage-Gate.

Table 1: Key Characteristics of Stage-Gate and Agile

Characteristic Stage-Gate Agile
Type of Model Macro-planning Micro-planning, project management
Scope Idea-to-Launch, end-to-end Development & Testing stages only
Organizational Breadth Cross-functional: Development (RD&E or technical), Marketing, Sales, Operations Technical (software code writers, engineers, IT people)
End Point A launched new product in the market Developed and tested working software product
Decision Model Investment model: Go/Kill Involves a senior governance group Largely tactical: the actions needed for the next sprint

Karlstrom and Runeson studied two large high-technology firms, in particular case studies integrating Stage-Gate and Agile development1. They note that “….software development projects are not isolated activities. They usually exist as sub-projects in an environment composed of hardware development, marketing, production planning etc. which all must be managed and coordinated concurrently.” The authors go on: “ [stage-gate methods] gives support not only for the communication within the project, but also for decision makers sponsoring the project or acquiring the outcome of the project.”

It's not a matter of either Stage-Gate or Agile. Agile is a very useful micro-planning or project management tool, and can be used effectively within the Development and Testing stages of Stage-Gate. But a new product project is much more than few stages in Figure 1.

Boehm and Turner discuss the contrasts between plan-driven software development and Agile approaches at length in their book2. Gate models in general are a form of plan driven models. One of the conclusions drawn in the book is that future projects will need both agility and discipline, which can be implemented by containing the Agile development methodology within the gate model.

What about Applying Agile to Hardware (or Physical Product) Development

With Agile and software development, each sprint or iteration produces a working product (executable software) that can be demonstrated to stakeholders (customers), as noted above. When contrasted to hardware development, the difference is that software development is divisible; hardware is not usually not divisible (i.e., you cannot build part of the product that actually works – thus it is not possible to have anything that actually functions within a few weeks).

Nonetheless, in next-generation versions of Stage-Gate designed for developing physical projects (i.e. hardware), starting this century, we began to build in spirals which are much like the sprints3,4. Spirals were introduced as a way to make the traditional 1990s model more adaptive and more responsive to fluid market conditions and changing product requirements.

Physical product developers: If you face a dynamic, fluid market with changing product requirements, be sure to employ spiral development - a series of build-test-feedback-revise iterations - with each iteration revealing a progressively more complete version of the product.

Here an iteration (between spirals) does not build a working product, but a product version somewhere between a “virtual product” through to a “ready-to-trial prototype”. Unlike software, each product version will not be a working product (until the end of the development stage), but will be something to show the customer to seek feedback. These product versions can be virtual prototypes, crude models, working models, protocepts, rapid prototypes, or early prototypes i.e. usually something physical that the customer can respond to – see Figure 1.

Bottom line: For physical product developers, it is usually impractical to employ sprints according to the software Agile model during the Development and Testing stages. But spirals – a series of build-test-feedback-revise iterations – are highly recommended to make the Stage-Gate system more adaptive5.

1 D. Karlstrom & P. Runeson, “Integrating Agile software development into stage-gate managed product development,”  Empir Software Eng (2006) 11: 203–225.

2 B. Boehm & R. Turner.  Balancing Agility and Discipline. Addison Wesley (2004).

3 R.G. Cooper and S.J. Edgett, Lean, Rapid and Profitable New Product Development, Product Development Institute (2005). 

4 R.G. Cooper, Winning at New Products: Creating Value Through Innovation, 4th edition. New York, NY: Basic Books (division of Perseus Books), 2011.

5 R. G. Cooper, Make your New Product Process Agile & Adaptable with ‘Spiral Development’. Stage-Gate Knowledge Community, Reference Article #35 (2008).

About Stage-Gate International

Stage-Gate International’s highly knowledgeable and experienced team of advisors have guided hundreds of organizations to successfully implement a best-practice Stage-Gate Idea-to-Launch process in as little as 4-8 weeks. We accelerate time-to-benefit with an extremely attractive return on investment by:

  • Crafting a balanced Idea-to-Launch Process Solution of expertise, advice, facilitation and best practices that fits your company’s situation, sense of urgency, and budget.
  • Collaborating with you so that your Idea-to-Launch process is implemented rapidly and your organization is equipped to ‘own’ and manage the process as quickly as possible.
  • Leveraging our market-leading accelerators, Benchmarker™ and SG Navigator™, to not only deliver all of the foundational elements straightaway, and ‘clear the path’ for rapid achievement of a  best-practice Idea-to-Launch process.

Dr. Robert G. Cooper

Robert G. Cooper is one of the most influential innovation thought-leaders in the business world today. He pioneered many groundbreaking discoveries in product innovation, including the Stage-Gate® Idea-to-Launch Process, now implemented by almost 80% of North American companies. Having spent 40 years studying the practices and pitfalls of 3000+ new product projects in thousands of companies, he has assembled the world's most comprehensive research in the field of product innovation management. His presentations and practical consulting advice have been widely applauded by corporate and business event audiences throughout the world, making him one of the most sought-after speakers.

A prolific author, Dr. Cooper has published 100+ academic articles and thirteen books, including the best-selling 'Winning at New Products', now in its 4th edition. He is the recipient of numerous prestigious awards including the Crawford Fellow from the Product Development and Management Association (PDMA) and the Maurice Holland Award from the Industrial Research Institute (IRI). He is also Professor Emeritus of Marketing and Technology Management at the DeGroote School of Business at McMaster University, and Distinguished Fellow at the Institute for the Study of Business Markets (ISBM) at Penn State University.