There are many strength training systems and all fit a someones training schedule and goal. Circuit, single set, super set or compound set just to name a few systems.
Ultimately it all comes down to three factors for every athlete. First factor is your goal. Is it strength, hypertrophy, sport specific what ever the goal it is always the first factor. If you want to gain strength you're not going to spend a bunch of sets at 15 reps it will not help you achieve your goal (unless you're an untrained or novice athlete).
If you know what you want to accomplish then it comes down to how many days a week and the hours or minutes you have to get in your training. This is often the hard part. If you are recreational lifter it's not that big a deal. But if you are training for a specific event it is a factor. As an athlete you just can't miss sessions.
Many of the athletes I work with have jobs, kids, a spouse as well as other commitments. So often times we have 30 to 40 minutes to get in the work. If it's a power day we spend our time there, but on strength days I like to compound set everything (depending on time we have to work). Compound set allow muscle groups to get more recovery time between lifts while doing more total body work. For example I'll have the athlete for 4 different widths on the bench and compound it with bent over row using different grips and width on the bar. This allows us to work chest and back at different angles with less total recovery time. So we can do more work in less minutes.
For more information contact Dennis DiCamillo MS, CSCS*D, NSCA-CPT*D at 909-560-5230