12 October 2008
The Switching Gears Factor
This summer we gave a presentation on simplifying the software estimation process for modern distributed systems. In it, we tried to boil down 10 years of thinking and experience on the subject; our goal was to make the process much more repeatable than it has historically been and as simple as is appropriate. On this particular day, a colleague from a client of ours approached me after the formal Q&A period and asked a question that demonstrated the level of hard-won expertise and critical thinking about estimation and project management she possess.
To paraphrase, she asked “I’ve developed my own techniques to estimate how working on multiple projects impacts a person’s productivity, what are your thoughts and references on the topic?” In essence, the topic of this question is what we — ALTERthought — call the switching gears factor. She inspired this post.
While the topic may seem tangential to the most important aspects of estimation and project management, it is, infact, one of the major reasons projects go over budget and off schedule. In the last 10-15 years, the popular notion of “multi-tasking” along with “doing more with less” have become culprits in causing teams to overload their professionals with multiple projects. This naturally impacts how effective a person is on any particular project. For many years, we’ve represented this concept as the productivity factor and have used it as a central tennant in project planning and estimation. It is so critical in planning, that we’ve codified it as a key variable in our software planning and estimation tool:Planix.
This, that, the other
Switching gears is not the common mistake of cramming excessive work into a shortened time frame, but the realiity of asking people to perform activities on a variety of different projects. Team members of different stripes can all relate to wearing not just different hats — but different hats for different initiatives. The software developer is asked to work on a new feature for an existing application, design for a completely new application, and bug fixing for an existing application — all contemporaneously. The project manager is asked to manage one project, perform business analysis for an upcoming project, and document the proceedings of the meeting for a third, maintenance initiative. The marketing manager is asked to survey customers for a recently released application, perform user acceptance testing for one in the pipeline, and to develop requirements for another.
Cry me a river
There is a strain of the business culture that would take the paragraph above as whining and the bemoaning of someone who strives for a project management utopia. Ahem. Where there is nobility and truth in the effectiveness of the American work ethic, there is delusion in the premise that every project is a high priority and will be completed as planned. In short, there is false optimism in thinking that we can have our cake and eat it too. It is precisely in response to realities such as the costs of multi-tasking and the rantings of the captains of “do more with less” that the Agile and eXtreme programming methodologies have increasingly gained in popularity. These approaches are fact-driven and deal with the reality of the company’s environment. Too many projects? Disparity in developer capability? Weak requirements? Overloading of team members? It all gets reflected in the concept of velocity.
The multi-tasking myth
It is true, that in modern American corporations — small and large — we all are and will continue to be asked to achieve “more with less.” What is not true is the common wisdom that simply asking for multi-tasking means people will accomplish more. Infact, social commentators, science and emerging popular coverage on multi-tasking demonstrate that multi-tasking means lost productivity – especially as the number of interruptions or activities increases. A relatively recent Vanderbilt brain imaging study (PDF file) demonstrates that as the time between interruptions decreases, the time required for a person to recover from the context switch and become productive again increases. We argue that this finding is analogous to and a by-product of increases in the number of projects assigned to a person. In common sense terms: As people are interrupted more, they get less done.
What does this mean for my project ?
Referring back to the original question posed by our colleague and client, a handful of people have analyzed how multiple assignments to any one individual costs an initiative and how to reflect it in project scheduling. Among the most notable is Gerald Weinberg (”Jerry”). In his classic book, Quality Software Management: Systems Thinking, Jerry proposes a rule of thumb for accounting for the context switching costs of working on multiple projects. Jeff Atwood’s blog, Coding Horror, gives a good summary of Jerry’s rule of thumb, so I won’t try to recreate it here.
Aside: for what its worth (its worth a lot) Jerry also takes a very sober – and sometimes critical view of our profession, consulting, in this book.
Shoulders of giants, math for you
Building on Jerry’s rule of thumb and the research from Vanderbilt, we propose our own rule of thumb that affords project planners an equation to quantify what working on multiple projects does to a person’s productivity.
Baseline Productivity
First, we build on our experience and existing research on productivity as an expression of productive hours worked in a week.
- The normal work week consists of 40 hours
- The most productive companies/people in the world are 80% productive;
- This is usually an outcome of life and the realities of a modern company: responding to e-mails, bathroom breaks, picking up the kids early from school, sending your rare burger back to the kitchen during a 2-hour lunch, doctor’s appointments — you get the idea
- So, what we have in world-class organizations is 32 productive hours per week (40 hours * .80)
- This productivity factor clearly will vary by the experience level of the professional involved
- You should adjust this productivity factor to represent the reality of your organization
That being said, this is an important departure from Jerry’s baseline assumption of 100% productivity (ie, 40 hours worked = 40 hours productive). Its also the basis for being able to construct a simple equation for modeling what happens to productivity as projects are added to a person’s plate.
Switching Costs & the productivity factor
If the most productive organizations and people in the world acheive 80% productivity on single projects, what happens when they begin to work on multiple projects? We propose and have observed the following: if your team members can achieve X% productivity on any single project, the cumulative effect of adding additional projects can be represented as a product of the productivity of the total number of projects to which they are assigned. So if x = a person’s productivity percentage on any single project and n=the total number of projects to which they are assigned, their total productivity can be reprsented by X% raised to the power of n.
Using our example of an 80% productivity factor, the equation Xn would yield the following chart of productive versus context switching time for 1 – 8 projects.
Looking at it a different way, with world-class, 80% productivity, the point at which a top-notch professional begins to spend more time context switching rather than being effective is at approximately 3 projects.
A Calculator
To calculate exactly how much productive versus context switching time occurs based on the total number of projects a person is assigned, use this calculator we created in Google Docs. Feel free to save your own excel copy (File > Export > .xls). The key variables you can change are as follow:
- Productivity factor (eg, 70%, 80%, 90%, etc)
- The number of simultaneous projects to which a person is assigned.
- he total work hours for an individual in a week (we recommend you be judicious about being overly optimistic of people being able to work more than 40 hours per week)
That’s it. Now, when negotiating with business stakeholders, hopefully, you’ll be able to more effectively demonstrate and account for the costs of assigning team members to multiple projects.
Technorati Tags: productivity factor, project management, estimation, context switching, switching gears factor, Jerry Weinberg, Gerald Weinber, multiple projects, multi-tasking, myth of multi-tasking
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ALTERthought Blogs » Speaking @ PMI - Central Virginia Chapter says:
ALTERthought Blogs » Speaking @ Tyson’s Corner PMI Luncheon Group says:
[...] On Tuesday March 24th, Sunjay Pandey will be speaking at the Project Management Institute’s Tyson’s Corner Area Luncheon Group . Sunjay will be reprising a topic entitled The Switching Gears Factor which describes portions of ALTERthought’s IT Governance approaches – particularly estimation and budgeting. In this session, Sunjay will discuss how the multi-tasking arising from multi-project assignments can impact IT projects. He will also discuss how it can be accounted for and how to manage this impact. Registration is available on-line. We look forward to seeing you there. digg_url = ‘http://alterlabs.com/uncategorized/speaking-tysons-corner-pmi-luncheon-group/’;digg_title = ‘Speaking @ Tyson’s Corner PMI Luncheon Group’;digg_skin = ‘compact’; reddit_url=’http://alterlabs.com/uncategorized/speaking-tysons-corner-pmi-luncheon-group/’reddit_title=’Speaking @ Tyson’s Corner PMI Luncheon Group’ del.icio.us [...]
ALTERthought Blogs » Speaking @ Norfolk Area PMI Dinner Group says:
[...] the Project Management Institute’s Norfolk Dinner Meeting. Sunjay will be presenting the topic: The Switching Gears Factor which describes portions of ALTERthought’s IT Governance approaches – particularly [...]
Multitasking Not Necessarily The Smartest Way To Work « Creating Engineers and Products for the Healthcare Industry says:
[...] The Switching Gears Factor [...]
[...] On Thursday, March 19th, Sunjay Pandey will be speaking at the Project Management Institute’s Central Virginia Chapter. Sunjay will be presenting a topic entitled The Switching Gears Factor which describes portions of ALTERthought’s IT Governance approaches – particularly estimation and budgeting. Specifically, Sunjay’s presentation discusses how multi-tasking negatively impacts project schedules and budgets and how to measure and manage this impact. Registration is available on-line. We look forward to seeing you there. digg_url = ‘http://alterlabs.com/general/news/speaking-pmi-central-virginia-chapter/’;digg_title = ‘Speaking @ PMI – Central Virginia Chapter’;digg_skin = ‘compact’; reddit_url=’http://alterlabs.com/general/news/speaking-pmi-central-virginia-chapter/’reddit_title=’Speaking @ PMI – Central Virginia Chapter’ del.icio.us [...]