In the good old days, most people worked on one and only one task. As we've learned to "work
smarter," this is less and less often the case — people split their time across several
tasks that need their particular expertise. Is this really smarter? What are the full costs
of dividing a person's attention?
Let's say, just hypothetically, that there are some people in your
organization who have some extraordinarily rare skills, knowledge, or talents. They're probably
in high demand. You've tried to hire more like them, but in today's market, it's next to
impossible. So somehow you live with what you have.
In many organizations, the "make-do" strategy of
choice is to time-share the people who have rare capabilities. We assign them 50% to this
project, 30% to a second, and 20% to a third. Oh, and if something else should come up now and
then, something short that needs their attention, they get to do that, too.
This might not be good management — it might not be your preferred way to work — but
that's life. In this note, I'll explore ideas that suggest that the costs of this arrangement
could be significantly higher than most of us ever imagined. My hope is that after reading
this, you'll take a look around your organization and see if there isn't some other way to deal
with the problem. And I'll give you some ideas for alternate strategies.
The importance of knowing the true costs of time-sharing a mind
When you assign a person to a task, you're using a model of how people manage their time.
That model contains a representation of how the work gets done, how the person manages time, and
how interactions occur on a team. For example, most of us assume that each person gives a full
day's work to the task assigned. And you might also assume that each person gives no work to any
other task. How realistic are these assumptions in project work? And how realistic are these
assumptions when someone is assigned to multiple tasks?
Since managing projects well requires that you manage costs, it's important to understand how
people manage their time, because professional people have to do time management largely without
supervision. To the extent that your model of personal time management accurately reflects how
people do it, your estimates of labor costs accurately predict actual costs.
The ability of professionals to manage their time is affected by the context in which they
find themselves. People use various time management strategies, and it's reasonable to suppose
that their choices are somewhat influenced by the number of projects they work on.
If part of your job is to use resources wisely, it pays to know how the manner of their use
affects their availability. In this essay, I'll explore some of those strategic choices and some
of the constraints the context places on those choices.
The hidden costs of split assignments
Life for people with multiple project assignments is complex. They must bear the cost of
dividing their attention, and since we rarely account for these costs in any explicit way, the
costs are buried — they appear only as depressed performance. Here are some examples of these
Split assignments usually increase the number of different activities that comprise a
typical day. The variety of intellectual contexts increases, along with the number of things
that you have to keep straight in your head. Whenever you switch contexts — shift gears —
you have to temporarily set aside one set of contextual facts, and slide another into place.
This is a costly operation that takes some time — depending on the individual and the
complexity of the work, it can be ten or fifteen minutes [DeMarco
87, p. 63]
Frequency of interruptions
Split assignments often increase the number of people you work with. And increasing the
number of people increases the chances that you'll receive a phone call, a page, or an
email. These increases lead, in turn, to more lost time by shifting
When you're on split assignment, your calendar is more complex. You have more meetings
to attend, more deadlines to keep in mind. The effort you must invest in calendar management
increases faster than the number of projects you support, because of interactions and
conflicts between calendar events, and because of further increases in the frequency of the
need to shift gears. Most important, the load presented to the
calendar management activity by a 50% task is roughly identical to the load of a 100%
Conflicts internal and external
The contention for time that you feel when you're on split assignment is a clear example
of conflicting priorities. But this conflict can also appear internally. Let's suppose that
you're on split assignment, and that you're achievement-oriented. Not an unlikely
combination — people who have performed well in the past are often in demand. Since you
can't give to each of your assignments the same focus and concentration that you used to be
able to apply to a single assignment, you can have a sense of conflict, not only between the
assignments, but between your desire to perform at high levels and your limited ability to
do so when on split assignment. This internal conflict is a source of stress, which can lead to depressed productivity and performance.
Damage to relationships
Another hidden cost is the damage done to relationships between the person on split
assignment and others. All kinds of relationships can be affected. For example, when you
have two project leaders, you have (at least) two — possibly conflicting — supervisory
relationships to manage. The conflicting priorities of two projects can lead to questions
about the personal loyalties and trustworthiness of the person on split assignment. If this
happens, the organization can suffer — perhaps not immediately, but in the long term,
certainly. This kind of damage is almost impossible to account for on a spreadsheet, but
it's very real. It can be a source of stress for everyone
Ah, stress! Stress in this context is a catchall for all the things that go wrong when
we take on too much. Too many meetings, too many conflicting priorities, and most
especially, too much work. Why too much work? Aren't two half-time assignments the same
amount of work as one full-time assignment?
In theory, they might
be, but because we fail so consistently to notice all the overhead items in this list,
somehow the gaps have to be closed. And if the people on split assignment are
achievement-oriented, they're the ones most likely to take responsibility for closing those
gaps. It usually means extra hours, maybe not at the office, but someplace. Maybe at home.
Or on the way to work. A shorter lunch perhaps. Unfortunately, extra hours can often mean
shoddy work due to fatigue, and for people who take pride in the quality of their
performance, this in itself is a source of stress. And of course, there are the other
factors: frequency of interruptions, conflicts internal and external, damage to relationships, and so on. It all leads to lower
productivity, higher rework rates, increased sick time, and
You might think, at first, that stress management training might
help, and it will, to some extent. But keep in mind that showing someone how to manage
stress better is second best; better still is to reduce the sources of stress. Consider an
analogy: starting a stress management education program instead of reducing sources of
stress is a lot like teaching pedestrians how to do self-surgery rather than building a
pedestrian bridge over the freeway.
How often do you have to redo what you've already done? For example, as I write this, I
make revisions. What you're reading is the result of my writing, and my rewriting. If I'm
really on a roll, my rewrite rate is lower than usual. Words come out, ideas come to me, and
the incidence of revisions drops. To get into that state, a state of flow, I need to focus
and concentrate my attention. To read more about flow, see [Csikszentmihalyi 1991]
When you're on split assignment, it's more difficult to get into
flow. Average rework rates are higher. Now, in itself, that may not be so bad in a project.
But consider what happens when average rework rates climb for a person whose role in a
project is central. I'm thinking about someone whose work affects the work of large numbers
of other project team members. If their work needs rework, it might happen that the work of
those who depended on the upstream results might also need revision. As a project leader,
it's important to make sure that rework rates are low for people whose output is far
Unfortunately, these "upstream producers" are just the kind of
people who can find themselves on split assignment. Uh-oh.
People on split assignments must write reports, just like people on single assignments.
The difference is that they write one report for each partial assignment. Thus the fraction
of their time spent reporting is somewhat higher than that of people with single
assignments. Not a big effect, you might think, but when you consider what happens to that
report, the little bits add up. It's processed through your project in just the same way as
your project process the report of a full-time team member. A team of 20 full-timers might
have to deal with 20 reports per time period. But if the 20 are actually full-time
equivalents, and there are really 32 people on the team, then we're talking about 32
reports, not 20. And correspondingly higher numbers of reminders to people who are late with
reports, higher numbers of reports to read, file, merge together, compare with each other,
and so on.
When a person on a half-time assignment must travel for that assignment, two things
happen. First, while on travel, they become full time. Second, the costs of travel —
airfare, food, lodging — are full costs, not half costs, even for a half-time team member.
Thus the cost of sending a part-time team member off site is sometimes unrecognized during
budgeting exercises. This happens because financial models sometimes model travel costs on
the basis of FTEs (full time equivalents) not on the basis of the number of people who
travel. Check your budget and cost proposal computations before you think about using
someone on a split-time assignment basis.
What is the cost of a meeting? Well, it's the hourly cost of each person attending
multiplied by the amount of time they invested in the meeting — including travel to and
from, preparation, attendance, breaks, everything. But meetings are like travel. Whenever people are attending a meeting, they're full time on the
project, whether they're dedicated to the project or assigned only part-time. When you use
split-project assignments, you raise the average time spent in meetings, relative to
Split-project assignments also increase the possibility of schedule
conflicts, especially for meetings that aren't regularly scheduled. Because such meetings
are more likely to be convened on short notice, schedule conflicts are often resolved using
phone calls, which raises the overall frequency of
What you can do
By now, you might be wondering how you can reduce the number of people who are on split
assignments. The obvious solution, hiring more people, is rarely practical. Downward pressures
on head count not only preclude this, but may even exacerbate the problem. Using contractors is
a possibility for some, especially if you have access to a source of reliable, competent people.
But there's a lot you can do that will reduce your reliance on the hiring process as a way to
address these problems.
Encourage technical mentoring
If you have someone with rare skills or knowledge, consider each project as an
opportunity for that person to mentor one or more others as they gain those skills. Use
projects as training opportunities — propagate capability throughout your
Use consultants as capability builders
In technical work, we most often use consultants to perform tasks directly, with little
effort spent transferring to our staff the skills the consultants have. Consider retaining
consultants — both internal and external — with the express purpose of educating your
people. This could help close your capability gap rapidly.
It just might be possible to coordinate projects in such a way as to avoid contention
for the same people. That is, if you can schedule an activity in one project so that it
doesn't overlap a similar activity in another, the people who have to work both activities
can do them one at a time, rather than simultaneously. This reduces the chances that someone
will be split across projects.
Cancel or delay projects
Is this project really needed now? Is it needed at all? It might be nice to get this
project done, but where does it really sit in the organization's priority list? When
answering these questions, consider the effects of splitting the time of the people who have
to work both projects. This may give you added reason to delay or cancel projects that
create contention for people with rare capabilities.
If you can't delay an entire project, perhaps you can delay or
reschedule those parts of it that create the greatest potential need to have split-time
If two projects are planning on building similar components, it might be possible to
make them identical. If it is, then they're built only once. Reuse does reduce direct costs,
but it also reduces contention for the time of those with specialized knowledge.
It might not be your practice to buy components built by other organizations, but if the
alternative is splitting the time of a number of people, the factors above might enter into
the build-buy decision.
Splitting people across projects can be like getting only $0.82 when you ask for change for
a dollar. You start out with one FTE, and by the time you deduct all the overhead costs of
splitting their time, you have much less than one FTE. The return on effort spent trying to
avoid split-time project assignments can appear immediately, and it can help lower the level
of frenzy in your organization. Top
DeMarco, T., and T. Lister. Peopleware: Productive Projects and Teams,
2nd edition. New York: Dorset House, 1999.
Csikszentmihalyi, Mihaly. Flow: The Psychology of Optimal Experience. New York:
Do you want to reduce the rate of split assignments in your organization? Through consulting
or coaching, I can help you to:
Contact me to discuss your specific situation, by email at rbrenner@ChacoCanyon.com or by telephone at (617) 491-6289, or toll-free at (866) 378-5470 in the continental US.
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