I run a small weekend car washing business to earn extra pocket money. I charge £8 for a standard wash and £15 for a full valet. I prefer washing blue cars because they look the best when they are clean, and I always listen to music on my headphones while I work. I need a simple app to record client bookings, track which cars have been washed, and calculate my weekly income.

The systems analyst needs to filter out the unnecessary details (such as the preference for blue cars) from this requirement description to focus only on what is essential to solve the problem.

Which computational thinking concept describes this process?