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TIMING IS EVERYTHING

by George Martin

Start ı Getting The Micro View ı Deciding Whatıs Big ı Establishing Task Dependencies ı Defining Critical Path ı Sources and PDF

For the past year, my articles have covered detailed issues in both hardware and software designs. These topics come from my direct experiences, which means I wrestled with those designs until I got them right. Iıd like to shift gears now and present a topic Iıve seen many engineers struggle withıscheduling a project.

As a designer, most of your time is probably (should be) spent doing design work. To me, thatıs the fun part. But, there are other aspects of your job that you need to do well so that customers can be satisfied. For example, you may need to create a bill of materials so the purchasing department can procure the parts or you may need to work with the test department to create a factory test setup.

And usually, to start a design, someone has to make a schedule and a budget for management to approve the project. Someday, youıre going to be the person scratching his/her head over when the prototype will be ready and how much itıs going to cost.

I believe the best schedule and budget you produce is one with no surprises. Sure, it would be easy to estimate twice as long and as much as you think it will take, but itıs a competitive world. Your competitors arenıt going to be that foolish. So, youıve got to produce realistic schedules and budgets.

Scheduling and budgeting go hand in hand. For this article, Iıll focus on scheduling and bring up budgeting where it makes sense.

NEAR-MISS SITUATIONS

What is a realistic schedule? You hear about a 90% confidence schedule, which means youıre 90% confident youıll make the schedule. To my way of thinking, it also implies that you miss one out of every ten. Although that might be a good approach in a larger company with more flexible staffing, my business canıt live with that. So, I approach scheduling with a more conservative view.

The basic building block of any schedule is a list of tasks to be completed. And, this is absolutely the most important thing to remember: you must create a list of all the tasks in your project. I canıt stress this enough. If you leave out or forget anything, youıve blown it! On your first attempt at scheduling, youıll probably leave something out. But donıt worry, itıs usually so painful that you never forget it againıat least, not that item.