The Mythical Man-Month

The Mythical Man-Month

The Documentary Hypothesis is the tenth essay of The Mythical Man-Month by Fred P. Brooks. This essay tackles the documents that a manager needs to focus and run his or her project. The topic of documentation in today’s project management environment often generates a very animated discussion, but as with many of the earlier essays, Brooks’ approach foreshadows lean or Agile approaches. The approach Brooks uses to identify the core documents is to identify the documents/data used to manage work in two non-software environments, perform a comparison and then to determine if there is a unifying thread. The final step in Brooks’ evaluated whether a common thread could be found and determined whether the information was required or useful in software projects.

The first type of work that Brooks used to identify the critical project management documents is the building of a piece commercial computer hardware.  The critical items identified were:

  1. Objectives
  2. Specifications
  3. Schedule
  4. Budget
  5. Organization chart
  6. Space allocations
  7. Market estimates, forecasts and prices

The relationships between forecasts, estimates and prices are used to show how changes can ripple through a project. For example, a change in the planned product price can affect the sales forecast; which then will impact the estimates of required materials and labor, the budget and might trigger a rethink of the specifications. Quoting Brooks:

“To generate a market forecast, one needs performance specifications and postulated prices the quantities from the forecast combine with the component counts from the design to determine the manufacturing cost estimate and they determine the per-unit share of development and fix cause these costs then determine price.”

These critical project management documents let a manager monitor changes in the project so the don’t become a vicious cycle.

The second type of work Brooks uses to illustrate his point is a university department. Brooks points out that the critical list of documents a manager uses to manage this type of work is very similar.

  1. Course descriptions
  2. Requirements for research proposals
  3. Plans for research when funded
  4. Class schedules and teaching assignments
  5. Budgets
  6. Space allocation
  7. Assignment of staff and graduate students

From these two lists, Brooks identified the common threads that a software project needs to start developing. They include an objective, product specifications, a schedule, a budget, space and an organization chart. These items define the who, what, when, why and with what for any effort. Regardless of methodology or framework, these “documents” are needed by every team, leader or project manager. The quotes around the word document reflect that the team doesn’t actually need to generate paper or a .docx file. For example, a fixed team and fixed duration is synonymous with a budget for effort.

The inclusion of an organization chart is an interesting twist. Brooks used the organization chart to introduce the idea of Conway’s Law into the Mythical Man-Month. Conway’s Law states law states that how an organization is structured influences the systems they develop. The organization chart reflects how an organization formally communicates which directly influences the design and development of functionality. This is due to the need to communicate to define, develop and maintain interfaces. Interestingly, in most IT organizations, you can use the existing interfaces between applications to identify boundaries between teams and physical departments. Conway’s Law is alive and well in the corporate world.

Brooks uses a computer product and university department to abstract what he believes is the informational core needed by a manager of a software project. But, why make these documents formal, when formal is shorthand for written down and sharable? Brooks provides three reasons.

  1. Writing decisions down exposes gaps and inconsistencies. The process of writing helps the writer to generate definitions that are clearer and more exact. As a writer, I concur (you never see my first drafts . . . and you don’t want to!).
  2. Documents (define this in any way you like, from wiki pages to an audio file) are an effective and efficient means of communicating decision. Documents create common knowledge quicker than relying on verbal communication paths alone. Documentation also reduces rehashing by providing a basis for common historical knowledge base.
  3. Documents provide a baseline that, when periodically reviewed, provides a manager with a method of identifying changes. All changes provide managers and teams with information that can be used to tailor behavior.

Many might bridle at the idea of documentation on general principle; however, all teams need to capture some core truths. What matters is less tools we use to capture the core information about any effort. Regardless of whether we use paper or something leaner or more agile, we need to document our core information. such as goals, objectives, backlog items, team norms or even a calendar of sprint activities.  The act of capturing information is an admission that we need structure to remember and refine a core set of information! The goal of documentation in any form is to guide behavior through communication.

Previous installments of the Re-read of The Mythical Man-Month

Introductions and The Tar Pit

The Mythical Man-Month (The Essay)

The Surgical Team

Aristocracy, Democracy and System Design

The Second-System Effect

Passing the Word

Why did the Tower of Babel fall?

Calling the Shot

Ten Pounds in a Five–Pound Package