\begin{figure*}
\renewcommand\baselinestretch{1}
{\scriptsize
\begin{alltt}
                                                                        consequence                error potential
phase           wbs                                     factor    1     2   3    4      5         1    2    3    4    5
--------------  ---    ---------------------------------------    ------------------------     ------------------------
concept         2.1                            Reuse Analysis*              X     X     X                                
                2.2           Software Architecture Assessment              X     X     X                                
                2.3                 System Requirements Review              X     X     X                        X    X
                2.4                Concept Document Evaluation                    Z     Z                             Z
                2.5   SW/User Requirements Allocation Analysis                    Z     Z                             Z
                2.6                      Traceability Analysis                    Z     Z                             Z
--------------  ---    ---------------------------------------    ------------------------     ------------------------
requirements    3.1      Traceability Analysis -  Requirements          X   X     X     X                        X    X
                3.2           Software Requirements Evaluation              X     X     X                        X    X
                3.3          Interface Analysis - Requirements                    X     X                   X    X    X
                3.4                  System Test Plan Analysis              X     X     X                                
                3.5              Acceptance Test Plan Analysis                          X                                
                3.6                 Timing and Sizing Analysis                                                   Z    Z
--------------  ---    ---------------------------------------    ------------------------     ------------------------
design          4.1             Traceability Analysis - Design                                         X    X    X    X
                4.2                 Software Design Evaluation                    X     X                        X    X
                4.3                Interface Analysis - Design                          X                        X    X
                4.4                 Software FQT Plan Analysis          X   X     X     X                                
                4.5    Software Integration Test Plan Analysis                                                   X    X
                4.6                          Database Analysis                                              X    X    X
                4.7               Component Test Plan Analysis                                                        X
--------------  ---    ---------------------------------------    ------------------------     ------------------------
implementation  5.1               Traceability Analysis - Code                          X              X    X    X    X
                5.2   Source Code and Documentation Evaluation                    X     X                   X    X    X
                5.3                  Interface Analysis - Code                    X     X                   X    X    X
                5.4                  System Test Case Analysis                    X     X                                
                5.5                 Software FQT Case Analysis                    X     X                                
                5.6          SW Integration Test Case Analysis                                                        X
                5.7              Acceptance Test Case Analysis                          X                                
                5.8     SW Integration Test Procedure Analysis                                                        X
                5.9       SW Integration Test Results Analysis                                                   X    X
                5.10              Component Test Case Analysis                                                        X
                5.11            System Test Procedure Analysis                          Z                               
                5.12           Software FQT Procedure Analysis                          Z                               
--------------  ----   ---------------------------------------    ------------------------     ------------------------
test            6.1               Traceability Analysis - Test          X   X     X     X                             X
                6.2                   Regression Test Analysis                                                  Z     Z
                6.3                        Simulation Analysis                          Z                                
                6.4               System Test Results Analysis                    X     X                                
                6.5              Software FQT Results Analysis                    X     X                                
--------------  ---    ---------------------------------------    ------------------------     ------------------------
other           7.1             Operating Procedure Evaluation                          Z                                
                7.2                         Anomaly Evaluation                          Z                                
                7.3                       Migration Assessment                          Z                                
                7.4                      Retirement Assessment                          Z                              
\end{alltt}}
\caption{
SILAP's  IV\&V tasks.
For definitions of each task, see~\cite{jackson97}.
For example, task 2.3
(System Requirements Review) is
selected if consequence is greater than 2
{\em or} the  error potential is greater than 3.
Tasks marked with  ``Z'' 
are only for human-rated flights. 
The asterik  on 
task 2.1 denotes a task that it selected when RA (re-use approach) is greater than 1.
Software phases
are numbered according to a NASA convention phase ``1'' is resevered
for management tasks conducted across the lifecyle. 
Phases 2,3,4,5,6 represent concept, requirements, design, implementation,
and test (respectively).
}\label{fig:silapModel}
\end{figure*} 
