My dad and I have been working out for about 1 years now and since I decided to put my routine on the site and get it tweaked, he decided to do the same thing. He has been a New York City Fireman for over 20 years and has seen improvements in work and everyday life since he started working out, though recently he has complained about elbow pain. He doesn't want to get big but rather stay skinny and get cut. This is what his current routine consists of:

(All excersises are done with 1 warm-up and 3 sets of between 6-10 reps)

Mon- Chest
Bench Press
Dumbbell Press
Dumbbell Flies

Tues- Tri's
Dips
Pushdowns
Bent over cable pushdowns

Wed- Bi's
Hammer Curls (Elbow Pain)
High Cable Curls
One arm preacher curls

Thur- Shoulders
Military Press
Rear Delt Raises
Dumbbell Presses

Fri- Back
Bent over rows (Elbow Pain)
Seated Rows
Lat pull down

Sat- Legs
Leg Press
Leg Curl
Leg Extension

Sun- Abs
Crunches
Oblique Crunches
Decline Reverse Crunches

Barbell curls can't be used because of pain. He usually takes the next day off after abs and starts over.

Is there any other kind of routine or a tweak of the current one to meet his goals? All posts are appreciated

I would recommend swapping your routine pretty much completely every 3 months or so (even just to relieve boredom and to keep motivated). For a start - stick in a rest day, second if you are after functional strength, do functional strenth exercises (where are you deadlifts, squats, lunges etc.)

I would also recommend that your Dad gets his elbow checked out - the routine that you are doing could be making the condition worse and worse (I ignored shoulder 'twinges' for years - big mistake!).