Application Upgrades and Service Oriented Architecture Page 3
lifecycle methodologies. Fundamentally, Carnegie Mellon as well as other experts
believe that proper Enterprise Architecture was often neglected during
implementations of packaged applications in the past.
But there is hope on the horizon. Service Oriented Architecture (SOA) with its
approach of “loosely coupling” has demonstrated that it can reduce maintenance
costs. For example, a study by SOA Industry Analyst Zapthink shows that
maintenance and change costs of SOA-based integrations, architected properly, are
dramatically lower than traditional integration approaches. The additional good
news is that core ERP and CRM Applications are now “service enabled”, meaning
they feature standard web services that can participate in a SOA. This includes
PeopleSoft (starting with PeopleTools 8.46), Siebel (starting with Siebel Tools 7.8),
JDE Enterprise One (starting with Tools 8.97) and E-Business Suite 11i (with the
Oracle E-Business Suite Applications Adapter).
THE BUSINESS CASE FOR SERVICE ENABLEMENT
This section will help you understand the impact that SOA enablement has on the
economics of an application upgrade. We will demonstrate how SOA enablement
can reduce the significant task of validating existing interfaces and customizations
in the later phase of an application upgrade.
In general, the upgrade process for a major point release, which in our experience
costs 18-20% of the initial implementation cost, can be broken into two phases:
• The process of applying upgrade scripts and testing core application
functionality followed by
• Testing and potentially re-working customer-specific customizations and
integration interfaces. Re-work includes re-establishing proper behavior as
well as also re-tuning for performance.
Clearly, phase two will vary based on the number of customizations and
integrations with external systems. In practice, we have found many cases where
testing became the most expensive part of the entire upgrade. A 50% split between
the two phases is typical. Very rarely have we seen the testing phase contribute less
than 30% of the overall costs.
When thinking about your individual application deployment, keep in mind that,
according to Carnegie Mellon’s Software Engineering Institute, the time needed to
conduct test and integration activities is often grossly underestimated. For example,
one upgrade scoped testing efforts at 1,600 hours and easily spent 10,000 hours.
To what degree can SOA-enablement reduced the cost of the phase two for testing
and potential re-work? One customer, a Fortune 100 company, explained that
before SOA, unexpected issues were often discovered late during the upgrade cycle.
“The real win with Service Oriented
Integration, therefore, is in the dramatic
reduction of cost at the maintenance and
change phases of integration”
— ZapThink: Understanding the Real Cost
of Integration
Data Points:
• Upgrade costs: 18-20% of initial
implementation costs
• 50% of the upgrade process related
to validating customizations &
integrations
• SOA reduces testing & re-work by 50-
75%
• Total upgrade cost reduction with
SOA: 15-38%
“The time needed to conduct test and
integration activities is often grossly
underestimated. For example, one upgrade
scoped testing efforts at 1,600 hours and
easily spent 10,000 hours”
— SEI, Carnegie Mellon