1. Timebox Development Instructor: Manfred Huber
test
Instructor: Manfred Huber
Partially adapted from Mike O’Dell and Bill Farrior

2. What is a Timebox?
DEADLINE
FUNCTIONALITY
CSE 4317

3. What is a Timebox?
A Rapid Application Development (RAD) technique that:
focuses on schedule
imposes a fixed time limit of a project
focuses on critical requirements
forbids (further) scope creep
does NOT work for all types of projects
very large projects
projects in core business area(s)
is often deployed with other RAD techniques, such as Evolutionary Prototyping, CASE, SWAT and JAD
CSE 4317

4. Why Consider Timebox? Things don’t always go as planned
Scope changes
Estimates were in accurate
People
Timebox Development provides a way to redefine the product to fit the schedule
Schedule is the priority
Avoids the “90% complete” problem
Controls product definition
CSE 4317

5. Need for a 90-Day Lifecycle
First used at DuPont
Scott Shultz
Documented by James Martin
“...Better to have a system of limited functionality working quickly than to wait two years for a comprehensive system.”
The application must be built so that it can be added to quickly
The two year wait...
CSE 4317

6. Scope Creep Problem
Users/developers keep adding  design slow to converge
By placing a rigid limit on delivery, developers are less inclined to experiment
Excessive functionality in software and electronic products often goes beyond usefulness
Enough,
already!
CSE 4317

7. The Timebox Approach Implementation/construction phase practice
Implement essential features first, then other features as (if) time permits
The product “grows like an onion” with the essential features at the core
Prototype and evolve approach
Requires heavy end-user/sponsor involvement
Usually last days
CSE 4317

8. The Timebox Product Rejected Timebox Development Build & Evolve
Prototype
System
Definition/
Priorities
Evaluate/
Deliver
System
Request for
Change
Prototype
End-user
Review &
Feedback
Review Board
Need for large-
scale change or
enhancement
CSE 4317

9. Review Board
Signs off on system definition (priorities) prior to timebox
Monitors progress
Evaluates completed system
YES / NO decision on completion.
Decision made quickly on each stage
Includes:
executive owner
user representative(s)
QA professional
CSE 4317

10. Timebox Requirements Clearly prioritized list of features
What’s essential and what’s not
Minimum core feature set
Realistic schedule estimate
Right kind of project
Ability for extremely rapid turn-around on prototypes (Evolutionary Prototyping?)
Sufficient end user involvement
Quick feedback is essential (JAD?)
CSE 4317

11. Variation: Parallel Timeboxing
Interfaces among subsystems determined, and held constant
Complex projects broken down into very small projects, which proceed in parallel
TIME 
CSE 4317

12. Dupont Experience
Extraordinary productivity improvements with Timeboxing on certain projects
80 function points per PM with Timeboxing vs without
No projects rejected with Timeboxing
Risk lowered/eliminated in many projects
CSE 4317

13. Summary: Timeboxing Advantages Disadvantages Speed
Quick feedback on basic functionality
Smaller teams reduce communication overhead
Problem tasks become visible
Can be used to save a doomed project
Disadvantages
May be attempted as a last-ditch effort on unsuitable projects
Improperly applied (wrong project or wrong approach), may sacrifice quality instead of features
CSE 4317

14. Keys to Success with Timeboxing
Only use for projects that can be implemented within days
Ensure that all stakeholders agree on minimum core feature set and prioritization of features
Be sure that team has bought in to aggressive Timebox schedule- and motivated properly to support it.
Focus on quality throughout the process
Cut feature if necessary, don’t extend the Timebox deadline
CSE 4317