# Expression management best practices/D.R.Y **URL:** \ **Category:** Ignition\ **Tags:** ignition81, perspective\ **Created:** [August 14, 2024, 5:33pm UTC](https://forum.inductiveautomation.com/t/expression-management-best-practices-d-r-y/94662 "2024-08-14T17:33:53Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\ **Post date:** [August 14, 2024, 5:49pm UTC](https://forum.inductiveautomation.com/t/expression-management-best-practices-d-r-y/94662/2 "2024-08-14T17:49:36Z")
> [@msteele](#): > > One dream is to have something like [Excel's Lambda function](https://support.microsoft.com/en-us/office/lambda-function-bd212d27-1cd1-4321-a34a-ccbf254b8b67), Hah! ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/f/3f1a7e762b58532d19ef54468b53c2a0bb340813.png) There's definitely the kernel of an idea there, an "expression library" or something. There's nothing, technically, preventing us from doing it, but I'm still not totally sure it passes the [-100 points rule](http://stronglyemergent.com/blog/2013/negative-100-points/). I can immediately think of at least four more-and-less significant drawbacks: - added complexity for less advanced users - "competition" with `runScript` - possible confusion of maintainers having to distinguish system expression functions, module expression functions, and user provided expression functions - interaction with (far) future plans for expression/scripting interpreting in Ignition Are those worth the added maintenance benefits to large scale systems trying to DRY things out? I'm not convinced yet, and the default position is "don't". --- _[View the full topic](https://forum.inductiveautomation.com/t/expression-management-best-practices-d-r-y/94662)._