In post-industrial business, the fine-grained cost accounting of the productive time of knowledge workers, especially creative professionals, has lost much of its meaning. Saving minutes here and there may produce more widgets, but it scarcely produces better ideas.

It is somewhat preposterous to expect creative professionals to do much meaningful work in the interstices between meetings, emails and other mundane obligations. Moreover, it is preposterous to expect them to invent on demand — to turn their creativity on at nine and off at five. Rather, it would make a great deal of sense to allocate and account for creative work in units of time that better reflect its shape. The unit I propose to accomplish this is the cell.

Imagine a cell as an elastic unit of time between three and four hours in length. The purpose of the cell is to stake out a contiguous block of time in which to do thought-intensive work — like a shipping container for time management. A cell is long enough for the necessary set-up and tear-down associated with the creative process, and provides ample space for minor events that occur in between. It can also be used as a corresponding unit of granularity for estimating and costing projects, and further as a unit of billing.

At approximately four hours per cell, a creative professional can reasonably allocate up to three per day, depending on his or her working arrangement. Within each cell is up to an hour in total for any kind of minor distraction from an impromptu discussion with a colleague to a coffee or bathroom break. The overall length of the cell is approximate to account for a better fit to individual peoples' schedules.

Each cell would be sandwiched between context switches, a configuration which offers a strong conceptual punctuation of activities, and can include activities like email, commuting to and from the office, or going to lunch. This arrangement affords a clean break from one activity to another, should the demands on one's time be diverse and urgent enough to require it. A core part of the theory is to get just the right amount of switches a day to best frame the kind of activities being done.

A cell is approximately congruent to a half-day of normal office work. A conventional North American work week would therefore contain ten cells out of a full complement of 21. A certain cell may be more appropriate for certain kinds of activities depending on its position in the day, week, month, quarter or year. For instance, a Monday-morning cell may be appropriate for meetings, communications and set-up activities for the week, whereas a Friday afternoon cell would be appropriate for maintenance or review. Summer cells could start earlier in the day and be spaced wide apart to take advantage of daylight and ambient temperature; winter cells could be packed closer together for the same reason.

Up next: planning and using cells. Following that, billing them.