WAYS TO DEFINE TRIPLE CONSTRAINT CATEGORIES

We want your project to limit its claims on common resources, both the time-based and spending-based kinds. At the same time, we’ve chosen this project because it has value (i.e., we want the eggs). There’s a minimum level of performance that achieves the value at an acceptable level—the level that’s truly good enough, not the “good enough” that implies merely squeaking by. A definition of “good enough” performance can include functional requirements—a round socket for a square filter—and also functional deadlines—before the CO2 levels reach dangerous or fatal levels. Definitions of “good enough” performance on cost and time also include different types of descriptions:

—Time constraint

• Specific deadline: On or before 1 October 2005.

• Event-related: Before the CO2 levels reach 12.

• Urgency: “I need this done yesterday! The boss is screaming for it!”

• Not urgent: Sooner is better than later, generally speaking.

—Cost constraint

• Cash: Budget, allowable cash expenditures—$2.6 million.

• Personnel: Team members, time-allocated resources (a “person-hour”)—3 engineers, 40 person-years.

• Equipment: Capital equipment, nonconsumables, fixed IT resources—a forklift and a crane.

• Supplies: Consumable supplies, paper, ink, toner—40 reams of 20# bond paper.

• Overhead: Costs charged to project budget for other organizational purposes (including G&A, profit, and all other loads).

• Intangibles (“political capital”): Ability to get support, favors, concessions—negotiation leverage, interpersonal skills, office politics, etc.

—Performance Criteria

• Functional requirements: Capacity, price, speed, storage, accessories, features—80 gigabyte hard drive, 2 Ghz Pentium V processor.

• Purpose: The desired end state, reasons why the project outcome is desired, goals to be achieved—“Reach $3 million in sales this year.”

• Evaluation criteria: Person or entity to be pleased, threshold to be met, objective or metric to be satisfied—“Get this product approved for sale in the European market.”

The categories first described are not necessarily the ones that turn out to be most important. “My new computer needs a 2Ghz chip!” This is a performance criterion stated in the form of a functional requirement. But that functional requirement may not be telling the real story. Perhaps we’d be better off as project managers if we knew why our customer needed a new computer in the first place and what he or she planned to do with it. Armed with a statement of purpose, we could evaluate the correctness or relevance of that functional requirement, and possibly suggest more and better ones to meet the customer’s real need.