# Feedback > ## 제어 이론 ## 제어 이론 - - ## [Lean software development](https://wiki.g15e.com/pages/Lean%20software%20development.txt) [LSD](https://wiki.g15e.com/pages/Lean%20software%20development.txt)의 원칙 중 하나인 [Amplify learning](https://wiki.g15e.com/pages/Amplify%20learning.txt)의 도구. Deterministic control doesn't work well with the variablility: > Imagine driving a car in which the position of the accelerator was preprogrammed at the factory. If you want to go 60 mph, it moves the accelerator to position A; if you want to go 65 mph, it moves the accelerator to position B, and so on. THis might work on flat terrain, but when it got to a steep hill, the car would slow to a crawl. Upon reaching the top, the car would careen dangerously fast down the other side. > > Deterministic control simply does not work when there is variablity in the terrain. --p26, Chapter 2, Increasing feedback: > In most cases, increasing feedback, not decreasing it, is the single most effective way to deal with troubled software development projects and environments. > > - Instead of letting defects accumulate, run tests as soon as the code is written. > - Instead of adding more documentation or detailed planning, try checking out ideas by writting code. > - Instead of gathering more requirements from users, show them an assortment of potential user screens and get their input. > - Instead of studying more carefully which tool to use, bring the top three candidates inhouse and test them. > - Instead of trying to figure out how to convert an entire system in a single massive effort, create a Web front end to the and try the new idea out. > > --p26, Chapter 2,