fisher'osu'edu

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Legacy Migration Case Study BMW FS US Mike
Alvarez Manager Application Architecture
Strategy, BMW Group, Financial Services Mark
Juras President, Great Migration, LLC

• fisher.osu.edu

Partnership for Performance
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Agenda

• Why are we here?
• History and Challenge.
• Critical Success Factors.
• Current Status and Lessons Learned.

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Why are we here?

• What makes this case study interesting and
  relevant
• Forced Migration (Microsoft pulling support for
  VB6 in 2008)
• Very difficult upgrade path to new Microsoft
  Platform (C/.NET)
• Many core business apps implemented or impacted
  by VB legacy code.
• Very compressed timeframe (3 years).

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History Challenge

• How we got here
• BMW FS US is primarily a Microsoft shop.
• Application development started when we were a
  much smaller company.
• Almost fifteen years of software development,
  use, and enhancement
• At least four hundred person-years of IT
  investment
• Our Challenge
• Migrate six very large mission-critical business
  systems
• Ensure total transparency to the business.
• Deal with the complications from varied
  architectures and applications.
• Over one million lines of VB6/COM code.

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Critical Success Factors

• Here are 3 critical success factors for our
  migration that you should consider
• Establish Guiding Principals
• Anticipate major decision points.
• Consider the 5 Pillars of a Migration Strategy

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Critical Success Factor 1 Establish Guiding
Principals Goals

• The effort will be gradual (3-year timeline)
  scheduled to complete prior to the Microsoft
  Visual Basic retirement date in March 2008.
• Minimize impact to business projects by aligning
  migration efforts with scheduled projects and
  avoiding code freezes.
• Strong commitment to research and analysis in
  year 1 required to get smarter about the
  challenges up front and enjoy more
  predictable/efficient migrations in year two and
  three.
• Leverage automated translation tools to the
  extent feasible
• Straight port business logic, but allow
  structural changes in cases where technical
  incompatibilities exist or where we can move to
  common frameworks.
• Architecture/Logic improvements acceptable if the
  cost of doing migration and project work together
  is lower than the cost of doing them separately.

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Critical Success Factor 2Anticipate the Major
Decision Points

• Funding, Timing, Capacity
• Skimming over not because of the lack of
  importance but because they are unique to each
  organization.
• Migration Approach
• Outsourced migration
• Code freezes may be longer and more of an issue
• Outsourcers cannot effectively test resulting
  code.
• Much effort required to collaborate with external
  team.
• Tool-centric migration
• Significant work to improve available
  tools/techniques is necessary
• Much effort required to develop migration
  standards.
• Package Replacement
• Solutions expand beyond the need of the
  migration.
• Wide-spread impacts to our landscape increasing
  the total costs.

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Critical Success Factor 3 Consider the 5
Pillars of a Migration Strategy

• A crucial part of our migration strategy were 5
  key processes aptly named the 5 pillars of a
  migration strategy which are applicable to the
  BMW FS migration strategy but can be applied to
  any migration strategy.
• Rearchitecting
• Translation / Migration
• Retooling
• Testing
• Managing

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Critical Success Factor 3 (contd)Consider the
5 Pillars of a Migration Strategy
Can we compare the different migration approaches
against the 5 pillars? Somewhat subjective but
the rationale is closer to the center is easier
and farther out is harder in terms of cost,
control, time, etc.
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Current Status

• Status
• VB Retirement is on Plan and on Budget
• Migration work is highly automated
• Migration work integrates easily with projects
  and maintenance.
• Lessons Learned
• Approach has worked well and met / exceeded
  expectations.
• Determining when to straight port vs. rearchitect
  or just rewrite is an art form. Success here
  varies depending upon who you ask.

For the full case study please reference the
article hosted at http//dotnet.sys-con.com/read/
299072.htm