However, knowledge of the processes and conditions that affect them is a great benefit for effective management. If you poke a complex system, it responds. But if you poke it again and try to very carefully do it the same as before, you may get similar results at first, but it quickly gives novel results that you wouldn't have expected from the first results. If you poke it again and try very carefully to do it as before, again the early results may be similar but quickly become unique. This results in surprises, more often than not.
Predictability is limited to early results.
To manage a complex system means that a manager must be able to detect early deviations from expectations quickly, and take actions to correct their undesired trends. If one waits too long, then the deviation is greater, and increasingly going awry which requires a strong action for adjustment. In a nutshell, the system quickly becomes unmanageable. Delayed responses after an action compound the difficulty of managing complex systems. The delay in response often means that the response being monitored shows a deviation from expected response after much has changed in other parts of the system, making it more difficult to know the factors that one should adjust to get the desired corrections.