Check the ratio of cumulative net profit to maximum drawdown. Examine the drawdown. It's the maximum equity drop from a high point in equity to the subsequent low point in equity until the high point in equity is breached to the upside. Essentially, it tells you the number of dollars you can expect to win for every dollar you put at risk. You should know your own risk propensity.
Some traders are willing to risk a dollar to make a dollar.
Others need more payoff for each dollar put at risk. Ask yourself how many dollars you would need to make on a given trade to motivate you to risk a dollar by taking that trade. That's the minimum ratio of profit to drawdown that you should accept. Make sure that the system's characteristics and performance are compatible with your temperament, style of trading, and the depth of your pockets. Instead of developing models based on recent price data, you might want to test data from previous time periods that closely resemble today's market conditions.