Re: Informix to Oracle migration

"Captain Pedantic" <theharlequin36_at_hotmail.com> wrote in message news:c1nda4$1k5p2g$1_at_ID-162943.news.uni-berlin.de...
| A potential customer has asked me to provide an estimate of how long it
will
| take to migrate their 4GL suite running on Informix "to Oracle".
|
| (I'm reminded here of Obnoxio's post of a while ago ridiculing another
| rather vague question: "I have a piece of string in my pocket. How long
is
| it? It's red by the way ...")
|
| Seriously, though, what sort of things should we be asking beyond these?:
|
| 1. Complexity of schema (what sort of things, other than serial, are going
| to be difficult to convert?)
| 2. Number of lines of 4GL
| 3. Number of stored procedures and triggers
| 4. Total number of tables
| 5 Volume of data
| 6. Availability of original programmers/BAs
| 7. Quality of documentation
|
| Assuming they don't want to re-write their app, they have to use a
| third-party "universal" compiler like 4Js or Querix (or of course
Websphere
| EGL, if they've the time to kill). Any other options?
|
| All (constructive) comments gratefully received.
|
| thank you.
| Capt. P
|
|

target platform?
essential business functionality? -- most 'migrations' need to fix badly implemented logic
quality of original design? -- how many kludges in the code? quality of data? -- how much cleaning will be required to move it to a normalized schema
how old is the app and what has happened to the business since then? what are users currently doing with the app? what are they doing to work-around its limitations? what goals were never met with the original app that could be achieved with the 'migration'?
what type of cutover period is anticipated? how will it be managed?

i really don't believe in 'migrating' an application without good analysis of the current state (health, usability, correctness) of the application and data, and then coming up with a strategy for balancing redesign, repair, and redeployment -- usually the same (or perhaps less) expense that is involved in attempting a technology migration will provide a more correct application

if possible, first give them an estimate for 'getting the string out of their pocket'

;-{ mcs Received on Fri Feb 27 2004 - 06:43:55 CST