>Arm extensions (triceps), 3 sets, 12-15 reps
>Chest press (chest, 3 sets, 12-15 reps
>Bicep curls (biceps), 3 sets, 12-15 reps
>Seated row (back), 3 sets, 12-15 reps
>Lateral raises (shoulders), 3 sets 12-15 reps
>Tricep dip machine, 3 sets, 12-15 reps
>Shoulder press, 3 sets 12-15 reps
In one of the books I read recently, the author made a very interesting point: if you're going to do three sets of an exercise for whatever body part, it's a good idea to do more than one exercise. Even to the point of doing three different exercises to make the total of three sets. This makes sense when you are short on time, especially.
I think this is a good idea especially for the smaller muscle groups, like biceps and triceps. I think the two tricep exercises you have are good, but you could vary the extensions by doing them a bit differently for each set (one as a tricep push-down using a bar, one as a seated oh extension, one as a lying extension).
For biceps, you could do one set straight curls, one set starting with a neutral (palms facing each other) hand position, and turning to a supine (palms up) position.
For chest press, I'd do at least one set on the incline.
The only thing I see missing is rear shoulder work. You could do some rear shoulder flyes to hit that area.
I think the basic workout looks good (but not necessarily in the order listed, which is sometimes working the smaller synergistic muscles, like triceps, before the larger muslces).
If you are running short on time, I'd keep the chest work (2 sets, one on incline) the back work (all three sets: I always think it's a good idea to do just a bit more work for the back than for the chest, or at least an equal amount, but never less, because we do so many pushing-dominant moves in everyday life we need the counterbalance of back work). Go heavy on these, and do them at the begining of your workout time (start with back, then chest , then back, then chest, then back). Then move to the shoulders and arms, and only do two sets of each instead of three, but remind yourself you're only doing two sets, otherwise, the subconscious mind, which is used to what you habitually do, will 'save some energy' for that 3rd set that's never coming.
DOing the chest and back in a push-pull manner will allow you to take less rest between sets, and make the workout go faster as well.
You can also save time by doing the shoulder and arm exercises in a circuit fashion: a shoulder exercise, followed by a bicep exdercise, followed by a tricep exercise. Then a short break, then repeat the sequence with the same or different exercises.
If you're used to doing straight sets (3 sets of exercises for X body part, done one after the other, with a break between sets), you may actually be able to do your whole workout in the same amount of time by using the push-pull and circuit order of exercises.
