My girlfriend uses a spreadsheet for her engineering work. She constantly complains about Excel running out of memory and crashing, and her work won't authorize the 64 bit version.

Basically she's importing time series data from sensors around the production plant, and then doing fairly complex engineering calculations. All of the formulas are pretty much textbook or derivation/substitutions thereof (e.g. different units, etc), but it's really crazy seeing them written as single line Excel expressions. She spends hours debugging single expression errors in the formulas written by herself and other engineers.

Since you asked for 2 examples, I used a spreadsheet for hosting cost estimation.

Have you suggested R?

I thought R was for statistics and not for mass balance equations. Graphing does seem plausible, that's sometimes what she does at the end.

EDIT: Even if she got it installed she'd have to the whole team to install it as well because they share data by emailing the spreadsheets.

R is for stats and data analysis in general. Should be able to do the same numeric computation that Excel can do.

If there is not a hard requirement for the data to be on-site, have you seen Google BigQuery and Fusion Tables?

https://cloud.google.com/products/bigquery/

https://sites.google.com/site/fusiontablestalks/stories

1) Creating an Estimate for fitting solar panels. 2) Storing orders for farm produce. 3) Stats/engineering calculations

Notes: These 3 are the main 3 that I have seen. i.e.

1) creating estimates. 2) mini database 3) Science/Stats/engineering calculations

I am working on this: www.cellmaster.com.au - so I ask people what they use spreadsheets for all the time.

Keeping track of time worked. It does the time arithmetics from the time I come and go.