
   Nick Haines sez;
   >(given that I've heard the Shuttle software rated as Level 5 in
   >maturity, I strongly doubt that this [having lots of bugs] is the case).

   Level 5?  Out of how many?  What are the different levels?  I've never
   heard of this rating system.  Anyone care to clue me in?

This is a rating system used by ARPA and other organisations to
measure the maturity of a `software process' i.e. the entire process
by which software gets designed, written, tested, delivered, supported
etc.

See `Managing the Software Process', by Watts S. Humphrey, Addison
Wesley 1989. An excellent software engineering text. The 5 levels of
software process maturity are:

1. Initial
2. Repeatable
3. Defined
4. Managed
5. Optimizing

The levels are approximately characterized as follows:

1. no statistically software process control. Have no statistical
   basis for estimating how large software will be, how long it will
   take to produce, how expensive it will be, or how reliable it will
   be.  Most software production is at this level.

2. stable process with statistical controls, rigorous project
   management; having done something once, can do it again. Projects
   are planned in detail, and there is software configuration
   management and quality assurance.

3. The process is defined and understood, implementation is
   consistent. This includes things like software inspection, a
   rigorous software testing framework, more configuration management,
   and typically a `software engineering process group' within the
   project.

4. Statistical information on the software is systematically gathered
   and analysed, and the process is controlled on the basis of this
   information. Software quality is measured and has goals.

5. Defects are prevented, the process is automated, software contracts
   are effective and certified.