What is a software blueprint?
Tags: webdev, software, uml, architecture
Published: 2021-07-17 11:15:28

A **software blueprint** is a **high-level plan** or outline used in the development of software.

When the term blueprint is used in programming, it usually refers to one of two related, yet slightly different concepts:

- a high-level, graphical or written piece of **documentation** of software architecture ("blueprint for **humans**")


- a piece of code serving as a template for **code-generating tools** that build or configure applications ("blueprint for **machines**")

Overall, software blueprints are a powerful tool for planning, building and maintaining software projects.

And first, let's take a look into how software blueprints are used **as documentation**.

## Blueprints as software design documentation

Blueprints may be used to **design** and **document the architecture** of applications. It serves as a **high-level representation of software design** that supports the development process in several ways:

As part of the planning process of upcoming feature work, a blueprint communicates **implementation requirements** across an engineering team more efficiently; a software architect may design a new feature and they can then use a blueprint to provide the feature requirements to the software engineers who will implement it later on.

In a similar manner, blueprints help teams consisting of both engineering and non-engineering professionals to collaborate on the development of business applications; blueprints empower stakeholders of either department to define requirements using common terminology that doesn't require in-depth, technical knowledge. This way, a **software blueprinting process** reduces the number of cycles needed for planning, implementing and iterating on features by getting application requirements defined well from the beginning. This in turn helps to **reduce the overall development time** of applications significantly.

![Title: An Architect in His Studio. Old ink drawing from the 19th century showing a man in a wealthy-looking coat sitting in front of his desk in his small studio room and working on a blueprint for a cathedral. You can see one of his employees in the background serving him tea](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/qo9v1ctvqki1xy58mlhv.jpg)

Through this process, blueprints become an effective strategy for maintaining documentation of software architecture. As a business goes through the iterative process of blueprinting feature work upfront and implementing features according to the design, a growing documentation for the business's software architecture is created automatically.

Using **Unified Modeling Language (UML)** software architects oftentimes visualize the design of the systems they and their team are implementing. Many products and open-source tools support software design with UML, such as [Papyrus](https://www.eclipse.org/papyrus/), [Visual Studio](https://visualstudio.microsoft.com/) or [Lucidchart](https://www.lucidchart.com/).

For more insight into the rationale behind **blueprints as documentation** and UML specifically, you may want to continue reading ["UmlAsBlueprint"](https://martinfowler.com/bliki/UmlAsBlueprint.html) by [Martin Fowler](https://twitter.com/martinfowler).

But the term blueprint isn't only used to describe software design plans that help **people** to implement said software. "Blueprint" also refers to those design plans that help **computers** to **implement software automatically**.

## Blueprints as automatic programming templates

In **automatic programming** a computer program, when run, generates code automatically based on a specific configuration. The configuration for these **code generators** can come from **direct user input** (e.g. parameters provided to a shell command) and - from **blueprints**.

![Old ink drawing of blueprints for the construction of the towers of the cathedral in Cologne, Germany](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/dz8f4r3b5m2v0uh0xjo0.jpg)

As part of the code generation process, the blueprint outlines the layout and configuration of the resulting program. This makes the blueprint useful in scaffolding and extending applications; a software engineer who uses blueprints in their development process can **focus** on the implementation of the **business logic** itself and worry less about how their implementation fits into the code base.

Therefore when used as **code generator templates**, blueprints improve the immediate developer experience significantly and can reduce overall development time. Lastly, they facilitate scaling and maintaining large applications by making extending applications easier.

Many different tools and **frameworks** already support blueprints and code generators for developers. This includes, for example and among many others, the [Python web framework Flask](https://flask.palletsprojects.com/en/2.0.x/tutorial/views/#create-a-blueprint), the [Blueprint visual scripting system of Unreal Engine](https://docs.unrealengine.com/4.26/en-US/ProgrammingAndScripting/Blueprints/), and the [JavaScript framework EmberJS](https://cli.emberjs.com/release/advanced-use/blueprints/).


## Blueprints as documentation and automatic programming tool

Blueprints are a **powerful tool** in planning, documenting and implementing software applications.

Blueprints - when used as documentation for software architecture - are critical for successfully planning and executing development cycles, whereas blueprints - when used as a template for code generators - are an integral part of maintaining and scaling code bases gracefully.

---

Have you created or used software blueprints before? Let me know in the comments below!