JACKET FIT

It is worth noting that in getting fit for the jacket that the shoulder darts and waist darts are used in a suitable way..sometimes the waist dart is made smaller as in width..and then perhaps lengthened if the jacket is hip-length..but if the waist dart is smaller then the shoulder dart is larger....does this make sense for the overall fit of the jacket....is it right...will a suitable fit always be given for all sizes..

I wonder if a suitable dart i.e. the waist dart extended to the hemline of the jacket is suitable in to-days fashions and manufacturing. Should such a co-called 'open-end dart' be used in to-days design/manufacturing...should darts be used...and are darts used...