DF = data.frame(
    subject=as.factor( 1:10 ),
    standard=c( 35.6, 31.3, 36.2, 31.1, 39.4, 34.7, 34.1, 36.5, 32.2, 40.7 ),
    vari_ject=c( 17.3, 16.4, 18.1, 17.8, 18.8, 17.0, 14.5, 17.9, 14.6, 16.4), 
    unimatic=c( 24.4, 22.4, 22.8, 21.0, 23.3, 21.8, 23.0, 24.1, 23.5, 31.3 ),
    tubex=c( 25.0, 26.0, 25.3, 24.0, 24.2, 26.2, 24.0, 20.9, 23.5, 36.9 )
)

library(reshape2)
DF_melt = melt(DF, id.vars=c('subject'), value.name='time', variable.name='system')