SIA Engineering and SATs are both subsidiaries of SIA and involved in mainly the same core business eg aviation although SATs do derive a substantial non-aviation revenue too from food catering. I did a simple 1HFY14/15 comparison of their results.
SIA Engineering SATs
Net Profit $95.6m $90.4m
Net Profit Margin 16.5% 10.3%
EPS 8.5 cents 8.1 cents
NAV 113.5 cents 112.6 cents
Cash & Cash Equiv $391.2m $338.4m
Debt to Equity Ratio negligible 0.08
Looking at their relative EPS, it will appear that SATs is a better bargain than SIA Engineering (at least for 1HFY14/15) taking into consideration that SIA Engineering and SATs traded recently at $4.15 and $2.96 respectively.However, like to take note that SIA Engineering underperformed in the last half year relative to their past history because of some undergoing structural changes in the industry.A lot boil down to whether they can reinvent to be on top of these changes and deliver the stellar performance as in the past. As for SATs, their performance has been flat over the last few years supported by a solid dividend policy and little debt.