# How to Perform a Project Estimation?

Time to Read 8 min

**"Divide et impera - divide and rule"** Gaius Julius Caesar

This isr the simpler and more popular case: a detailed specification (a requirements specification) and a rough technical solution (a system architecture) already exist for a project.

## More than 100 Pages of Specification and still No Coffee?

An example of this was the development of a control system for a professional coffee machine. In order to easily operate the coffee machine with its variety of products and with the numerous configuration options, product and cleaning processes, languages and maintenance options, a fully graphical touch screen was specified. This resulted in software that was further complicated by the many dependencies on the hardware and especially the mechanics of the machine.

The finalized specification contained more than a hundred pages, plus the same amount of description of the mechanical processes. With this information, a more accurate project estimate for a fixed price project was possible. In the end, the entire project to the finished control system involved several person-years of work. This entire project was estimated by our engineers at the beginning to be more accurate than a 10% variance. And all this without even having smelled the first espresso from the machine ...

### What Can You Expect?

**Work Breakdown Structure**: What it looks like and why it requires a system design**Project Structure and Project Life Cycle**: Reuse helps save time!**Effort Estimation as a Team**: How the estimates come together... and the risks**Two-Point Estiamtion**: How the worst case gets into the estimation**Parameter Estimation**: Where you can keep your work easy

And on separate pages:

**Estimation: What Should be Considered in Practice?****Models: How to Deal with Fuzziness? Distributions!**

We have been working with this estimation method for many years and have developed a spreadsheet template for it. In addition, a software tool exists for this project estimation, which we offer as freeware if there is enough interest, please comment below if you are interested.