When designing and subsequently estimating a solution for a project can be daunting, where do you start?
Working on a project where you have some familiarity with the type of problem being solved allows you to start with a point of reference. Being able to look at a set of requirements and compare it to a previous project allows you to answer questions like: Is it more complex? What is the same? What is different? What are the risk areas?
Using a previous project gives you a point of reference that is factual, you can see what the project actually cost you and you can see the issues that it had to deal with. There is a wealth of history that you can use as an outline for the project you are assessing. There are the variations between the planned design and the planned cost versus the actual design that was implemented and the actual cost of the project also draw out some interesting insights.
I like a quote from Mark Twain:
“History doesn’t repeat itself, but it does rhyme.”
Someone new to Architecture can look at the task ahead of them and think all they have is a blank sheet of paper but often they have a lot more than that. Although they may not have been involved with an end to end solution like the one before them I am sure they have experiences. It is often a case of being able to look at the Architecture problem before you and being able to map it to a lower level experience from your past. Building a logging service for a project 2 years ago may be just the experience that you can plug into the design in front of you, it may be only a small part but you can say with confidence that the design and the cost are correct.
Draw on other peoples experience this can be other people you have worked with that you know have done something you can reuse. Ring Sam who you used to work with who built a mobile application similar to the one you are designing for the current project. Get to know some other Architects, ask around who has experience with projects similar to yours. A real eye opener is when you ask around and find out that the business tried to get this project up and running two years ago and Robert one of the Architects worked on it and has the design from when he worked on it. Don’t laugh it has happened to me more than once.
So don’t ever start with a blank sheet of paper you have experiences that you can draw on and add to this with past experience from other people. Architects are often more than happy to share a past project with you.