Since its creation, the spiral model has
been extensively elaborated2 and successfully
applied in numerous projects.3,4
However, some common difficulties led
USC-CSE and its affiliate organizations to
extend the model to the WinWin spiral
model described in the main text.
Negotiation front end
One difficulty was determining where
the elaborated objectives, constraints, and
alternatives come from. The WinWin spiral
model resolves this by adding three
activities to the front of each spiral cycle,
as Figure A shows.5
• Identify the system or subsystem’s key
stakeholders.
• Identify the stakeholders’ win conditions
for the system or subsystem.
• Negotiate win-win reconciliations of
the stakeholders’ win conditions.
We have found in experiments with a
bootstrap version of the WinWin groupware
tool that these steps do indeed produce the key product and process objectives,
constraints, and alternatives for the
next version.6 The model includes a stakeholder
WinWin negotiation approach that
is similar to other team approaches for
software and system definition such as
gIBIS, Viewpoints, Participatory Design,
and Joint Application Design. However,
unlike these and other approaches, we use
the stakeholder win-win relationship as the
success criterion and organizing principle
for software and system definition. Our
negotiation guidelines are based on the
Harvard Negotiation Project’s techniques.