When the Spreadsheet Hits the Fan

Most of us use spreadsheets for all sorts of things. The spreadsheet and the word processor are the work horses of most computer tasks in the home or the workplace. It is not surprising that when faced with a scheduling task, we have turned to the tools we know best. And sometimes they work great and that’s all we need. But all too often we find it difficult to cast our scheduling problem into the rows and columns required.

Why is that?

To start with, the spreadsheet is fundamentally a table–a two-dimensional representation of data relationships. But the natural data structure for scheduling is more like a tree–a hierarchic structure.

Here’s what I mean: Let’s say we’re talking about meetings. One meeting requires a room and three people. The other meeting requires a room, four people and a projector. Notice that the first activity points to four required resources, and the second activity points to six required resources. If I make each column an interval of time, then what are the rows?  I can make each row a person or a room or a projector and then try to find the time intervals (columns) when all are available simultaneously, or I can make each row an activity but then I have to look elsewhere for times when all the resource are free. Ugh!

The fact that scheduling can be regarded as a dynamic manipulation of tree structures can be credited to one of my old colleagues, Dr. Rudy Ramsey, who is an expert in the field of human factors in computer systems. (In fact, Dr. Ramsey and Dr. James Van Doren built a tree-manipulation programming language that proved ideal for building scheduling applications.)

There is another limitation imposed by the spreadsheet. In my meetings example, I assumed that the columns were intervals of time such as hours, or days (like a calendar). What if the meetings were 20 minutes long but the columns in a scheduling spreadsheet represented 15-minute intervals? How many columns do I use to schedule a 20-minute activity? This might not seem important for a meeting schedule, but if the activities were baking 100,000  gourmet chocolate chip cookies, the duration better be precise! The same holds true for other manufacturing activities– right? Spreadsheets almost always require using time buckets. (Checkout my previous post on the subject of time buckets here:  http://schedulingdoneright.com/time-is-a-continuum/

We need a scheduling tool that doesn’t force us into using time buckets!

So, let me propose that we add a good time-based planning tool to the home/office toolkit. We should have a

  • Word processor
  • Spreadsheet
  • Presentation builder
  • Mail program
  • Calendar/reminder application, and
  • A generic scheduler

So whether you’re scheduling meetings, mass production of chocolate chip cookies, or anything else, it just makes good sense. And as we all know by now, good sense = good cents.