Communication in Migration Projects – The Mapping Specification

Jan 18, 2018 | by Antje Dwehus

Blogpost | Header | Communication in Migration Projects - The Mapping Specification

Who hasn’t already made the painful experience of how bad communication has led to additional costs and reduced the quality of a project at the same time? We don’t want that to happen at all and therefore most project leaders today are very aware of the importance of communication within their project.

To help keeping your communication straightforward in a migration project, let’s have a closer look at the mapping specification as a crucial document in migration projects.

Mapping Specification

The mapping specification defines which element (in the majority of cases this will correspond to an attribute) from the source system is mapped to which element in the target system and what kind of transformation rule is applied during this process.

Our best practice is to list each element, even if there will be a simple 1:1 mapping or information won’t get migrated to the new system at all. This makes the list complete, comprehensible and ready for adaptions in case of changes – which we would love to prevent, but, as we know, are likely to occur as the project moves on.

Transformation Rules

Very important when defining the transformation rules is the definition of exceptions. For example what if:

  • An author in the source system doesn’t exist anymore in the target system because he/she has left the company.
  • An attribute contains a value that is not expected, like a state 5 when only having defined mapping values 1 to 4 (see table 2 below)

Please note that the argument “It’s not possible.” should only be a reason for not defining an exception rule after thoughtful analysis.

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Mapping Tables

In most of the projects, Excel files are sufficient for the migration specification. They should contain the mapping tables on dedicated sheets. If the file is stored at a central location, preferably a system with version control and accessible by the project team, everybody is up-to-date at any time.

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A detailed mapping specification is a must-have in all migration projects. All team members have to be able to access it. It should be a binding document and updated in case of changes during the running project. In most projects, MS Excel is the tool of choice for creating and maintaining the mapping specification.

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Mapping rule exception for document owner as seen under Transformation Rules listing point 1