Every day, we do something or the other, either at home or the place of work. At times we find that we are pressed for time; at times we might run short of other resources such as spares and tools. When you look back and analyse the reasons for such occurrences, we may find that we did not plan the jobs well and arrange for all the resources including time before we actually started the job.
When you do not plan and schedule your tasks, the probability of problems cropping up is high. The added risk is the increase in stress and strain related to the anxiety to finish the job well. This could lead to increase in the pace of work and likelihood of minor accidents, drop in quality of work etc.
The article linked below makes good reading with down to earth examples and simple language.
Read, enjoy and assimilate the principles.