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ERP Migration

The Critical Role of Data Cleansing in Legacy ERP to Modern Platform Migrations

Discover why data cleansing is the most critical phase in ERP migration. Learn practical steps for profiling, deduplication, and validation to ensure a successful cutover.

17 min readSysGenPro Editorial
The Critical Role of Data Cleansing in Legacy ERP to Modern Platform Migrations

Data Cleansing Is the Foundation of Successful ERP Migration

The critical role of data cleansing in legacy ERP to modern platform migrations is to ensure that business data is accurate, complete, and consistent before it is loaded into the new system. Migrating dirty data from a legacy environment into a modern ERP platform amplifies existing errors, breaks business processes, and undermines user trust in the new system. The recommended approach involves a structured data governance process that includes profiling, cleansing, transformation, and validation. This phase is not merely a technical task but a business initiative that requires ownership from finance, operations, and IT leaders. The main risks to control include data loss, duplicate records, broken integrations, and reporting discrepancies that can halt operations during cutover. By treating data cleansing as a prerequisite rather than an afterthought, organizations can reduce migration risk, protect operational continuity, and ensure that the new ERP platform delivers its intended value.

Understanding the Data Landscape in Legacy Systems

Legacy ERP systems often accumulate years of data inconsistencies due to manual entry, lack of validation rules, and multiple system integrations. Before any migration work begins, a comprehensive data profiling exercise is essential. This involves analyzing the source data to identify patterns, anomalies, and quality issues. Key areas to profile include master data such as customers, vendors, and products, as well as transactional data like sales orders and invoices. Profiling helps determine the volume of data, the complexity of the schema, and the extent of cleansing required. It also reveals hidden dependencies between data fields that may not be apparent in the user interface. Understanding this landscape allows project teams to estimate the effort required for cleansing and to identify high-risk data sets that need special attention.

Identifying Data Quality Issues

Common data quality issues in legacy systems include missing mandatory fields, inconsistent formatting, duplicate records, and obsolete data. For example, customer addresses may be stored in different formats across different regions, or product codes may not follow a standard naming convention. These issues can cause significant problems during migration if not addressed. Duplicate records can lead to fragmented customer views and inaccurate reporting. Missing data can prevent the creation of valid transactions in the new system. Obsolete data, such as inactive vendors or expired products, increases the volume of data to be migrated and can clutter the new system. Identifying these issues early allows teams to prioritize cleansing efforts and to define clear rules for handling each type of problem.

Assessing Data Volume and Complexity

The volume and complexity of data in a legacy system can significantly impact the migration timeline and cost. Large data sets require more time for profiling, cleansing, and validation. Complex data structures, such as those with many related tables or custom fields, require more sophisticated mapping and transformation rules. It is important to assess whether all historical data needs to be migrated or if only a subset is required for business continuity. For example, transactional data older than a certain period may not be needed in the new system if it is archived in a separate repository. Making this decision early can reduce the scope of the migration and focus resources on the most critical data. This assessment should be done in collaboration with business stakeholders to ensure that the data retention policy aligns with business needs and regulatory requirements.

The Data Cleansing Process: Step-by-Step Approach

A structured data cleansing process is essential to ensure that data is ready for migration. This process typically involves several key steps: extraction, profiling, cleansing, transformation, and validation. Each step requires careful planning and execution to ensure that data quality is maintained throughout the migration. The process should be iterative, with multiple rounds of cleansing and validation to catch any issues that may arise. It is important to document all cleansing rules and transformations to ensure that the process is repeatable and auditable. This documentation is also useful for troubleshooting any issues that may arise during or after the migration.

Extraction and Profiling

The first step in the data cleansing process is to extract data from the legacy system. This should be done in a controlled manner to ensure that the source system is not impacted. The extracted data should be stored in a staging environment where it can be analyzed without affecting production operations. Once the data is in the staging environment, profiling tools can be used to analyze the data for quality issues. These tools can identify missing values, inconsistent formats, and duplicate records. The results of the profiling exercise should be documented and shared with business stakeholders to get their input on how to handle each type of issue. This collaboration is essential to ensure that the cleansing rules align with business needs.

Cleansing and Transformation

Once the data has been profiled, the next step is to cleanse and transform it. Cleansing involves correcting errors, filling in missing values, and removing duplicates. Transformation involves converting the data into the format required by the target system. This may include changing data types, reformatting dates, or mapping legacy codes to new system codes. These processes can be automated using data cleansing tools, but manual review is often required for complex or ambiguous data. It is important to define clear rules for each cleansing and transformation step and to document them. This ensures that the process is consistent and that any issues can be traced back to their source. The cleansed and transformed data should then be validated to ensure that it meets the quality standards defined by the business.

Deduplication and Record Matching

Deduplication is one of the most challenging aspects of data cleansing in ERP migrations. Legacy systems often contain duplicate records for customers, vendors, and products due to manual entry errors or lack of validation rules. These duplicates can cause significant problems in the new system, such as fragmented customer views and inaccurate reporting. Deduplication involves identifying and merging duplicate records into a single, accurate record. This process requires careful matching rules to ensure that records are correctly identified as duplicates. For example, two customer records may be considered duplicates if they have the same name, address, and phone number. However, it is important to be cautious with matching rules to avoid merging records that are actually distinct. This process should be done in collaboration with business stakeholders to ensure that the matching rules align with business needs.

Matching Rules and Algorithms

Effective deduplication requires well-defined matching rules and algorithms. These rules should be based on a combination of exact matches and fuzzy matches. Exact matches are used for fields that should be identical, such as tax IDs or email addresses. Fuzzy matches are used for fields that may have slight variations, such as names or addresses. The choice of matching algorithm depends on the nature of the data and the level of accuracy required. It is important to test the matching rules on a sample of the data to ensure that they are working correctly. This testing should be done in collaboration with business stakeholders to ensure that the results are acceptable. Any issues identified during testing should be addressed before the deduplication process is applied to the full data set.

Handling Ambiguous Records

Not all duplicate records are easy to identify. Some records may be ambiguous, meaning that it is not clear whether they are duplicates or distinct records. These records require manual review to determine the correct action. This review should be done by business stakeholders who have a deep understanding of the data and the business processes. The results of the manual review should be documented and used to refine the matching rules for future iterations. This iterative process helps to improve the accuracy of the deduplication process and to reduce the number of ambiguous records that require manual review. It is important to allocate sufficient time and resources for this manual review to ensure that it is done thoroughly and accurately.

Data Mapping and Transformation Rules

Data mapping is the process of defining how data from the legacy system will be transformed into the format required by the target system. This involves mapping fields from the source system to fields in the target system, as well as defining any transformations that need to be applied to the data. For example, a legacy system may store dates in a different format than the target system, or it may use different codes for product categories. These differences need to be addressed in the data mapping process. It is important to document all mapping rules and transformations to ensure that the process is repeatable and auditable. This documentation is also useful for troubleshooting any issues that may arise during or after the migration.

Field-Level Mapping

Field-level mapping involves defining how each field in the source system will be mapped to a field in the target system. This requires a detailed understanding of the data structures in both systems. It is important to consider not only the data types but also the business meaning of each field. For example, a field that is optional in the source system may be mandatory in the target system. In this case, a default value may need to be assigned to the field during the transformation process. It is also important to consider any dependencies between fields. For example, a product category may need to be mapped to a specific value in the target system based on the product type. These dependencies need to be carefully defined and tested to ensure that the data is transformed correctly.

Transformation Logic

Transformation logic involves defining the rules that will be applied to the data during the migration process. This may include changing data types, reformatting dates, or applying business rules. For example, a legacy system may store currency values in a different format than the target system. In this case, a transformation rule may need to be defined to convert the currency values to the correct format. It is important to test the transformation logic on a sample of the data to ensure that it is working correctly. This testing should be done in collaboration with business stakeholders to ensure that the results are acceptable. Any issues identified during testing should be addressed before the transformation logic is applied to the full data set.

Validation and Reconciliation

Validation and reconciliation are essential steps in the data cleansing process to ensure that the data is accurate and complete before it is loaded into the target system. Validation involves checking the data against a set of predefined rules to ensure that it meets the quality standards defined by the business. Reconciliation involves comparing the data in the source system with the data in the target system to ensure that it has been migrated correctly. These processes should be done in multiple rounds to catch any issues that may arise. It is important to document the results of the validation and reconciliation processes to ensure that the data is auditable. This documentation is also useful for troubleshooting any issues that may arise during or after the migration.

Automated Validation Rules

Automated validation rules can be used to check the data for common quality issues, such as missing values, inconsistent formats, and out-of-range values. These rules can be defined based on the business requirements and the data model of the target system. For example, a validation rule may check that all customer records have a valid email address, or that all product records have a positive price. These rules can be automated using data validation tools, which can significantly reduce the time and effort required for validation. It is important to test the validation rules on a sample of the data to ensure that they are working correctly. This testing should be done in collaboration with business stakeholders to ensure that the rules align with business needs.

Manual Reconciliation

Manual reconciliation is required for data that cannot be validated automatically, such as complex business rules or ambiguous records. This process involves comparing the data in the source system with the data in the target system to ensure that it has been migrated correctly. This can be done by comparing key metrics, such as the total number of records, the total value of transactions, or the number of active customers. Any discrepancies identified during the reconciliation process should be investigated and resolved before the data is loaded into the target system. This process should be done in collaboration with business stakeholders to ensure that the discrepancies are understood and addressed.

Roles and Responsibilities in Data Cleansing

Data cleansing is a cross-functional effort that requires collaboration between IT, finance, operations, and other business units. It is important to define clear roles and responsibilities for each stakeholder to ensure that the process is managed effectively. The IT team is responsible for the technical aspects of the cleansing process, such as data extraction, transformation, and validation. The business stakeholders are responsible for defining the cleansing rules, reviewing the results, and making decisions on how to handle ambiguous data. The project manager is responsible for coordinating the efforts of all stakeholders and ensuring that the process is on track. It is important to establish a governance structure that includes regular meetings to review progress, resolve issues, and make decisions. This structure helps to ensure that the data cleansing process is managed effectively and that any issues are addressed promptly.

Business Stakeholder Involvement

Business stakeholders play a critical role in the data cleansing process. They have the knowledge and expertise to define the cleansing rules, review the results, and make decisions on how to handle ambiguous data. It is important to involve business stakeholders early in the process to ensure that their input is considered. This involvement should be ongoing, with regular meetings to review progress and resolve issues. It is also important to provide business stakeholders with the tools and training they need to participate effectively in the cleansing process. This may include access to data profiling tools, training on the cleansing rules, and support from the IT team. By involving business stakeholders in the cleansing process, organizations can ensure that the data is cleansed in a way that aligns with business needs.

IT Team Responsibilities

The IT team is responsible for the technical aspects of the data cleansing process. This includes data extraction, transformation, and validation. The IT team should have the skills and tools needed to perform these tasks effectively. This may include data cleansing tools, database management skills, and programming skills. The IT team should also be responsible for documenting the cleansing process and providing support to business stakeholders. This documentation should include the cleansing rules, the transformation logic, and the validation results. By providing this documentation, the IT team can ensure that the cleansing process is auditable and that any issues can be traced back to their source. The IT team should also be responsible for testing the cleansing process in a staging environment to ensure that it is working correctly before it is applied to the production data.

Risk Management and Mitigation Strategies

Data cleansing in ERP migrations carries several risks, including data loss, broken integrations, and reporting discrepancies. It is important to identify these risks early and to develop mitigation strategies to address them. One of the main risks is data loss, which can occur if the cleansing process is not done carefully. To mitigate this risk, it is important to create backups of the source data before any cleansing is done. These backups should be stored in a secure location and tested to ensure that they can be restored if needed. Another risk is broken integrations, which can occur if the data is not transformed correctly. To mitigate this risk, it is important to test the data in a staging environment before it is loaded into the target system. This testing should include integration tests to ensure that the data is compatible with the target system's integrations.

Data Loss Prevention

Data loss is one of the most serious risks in ERP migrations. It can occur if the cleansing process is not done carefully, or if the data is not backed up properly. To prevent data loss, it is important to create backups of the source data before any cleansing is done. These backups should be stored in a secure location and tested to ensure that they can be restored if needed. It is also important to use version control for the cleansing scripts and rules to ensure that any changes can be tracked and reverted if needed. By taking these precautions, organizations can reduce the risk of data loss and ensure that the migration process is safe.

Integration Failure Mitigation

Integration failures can occur if the data is not transformed correctly or if the target system's integrations are not compatible with the migrated data. To mitigate this risk, it is important to test the data in a staging environment before it is loaded into the target system. This testing should include integration tests to ensure that the data is compatible with the target system's integrations. It is also important to coordinate with the integration team to ensure that any changes to the data model are communicated and implemented correctly. By taking these precautions, organizations can reduce the risk of integration failures and ensure that the migration process is successful.

Post-Migration Data Monitoring and Support

Data cleansing does not end with the migration. It is important to monitor the data in the new system to ensure that it remains accurate and consistent. This monitoring should include regular checks for data quality issues, such as missing values, inconsistent formats, and duplicate records. It is also important to provide support to users who may encounter data issues in the new system. This support should include a process for reporting and resolving data issues, as well as training for users on how to use the new system effectively. By providing ongoing monitoring and support, organizations can ensure that the data in the new system remains accurate and consistent, and that users are able to use the system effectively.

Ongoing Data Quality Monitoring

Ongoing data quality monitoring is essential to ensure that the data in the new system remains accurate and consistent. This monitoring should include regular checks for data quality issues, such as missing values, inconsistent formats, and duplicate records. These checks can be automated using data quality tools, which can significantly reduce the time and effort required for monitoring. It is important to define clear metrics for data quality and to track these metrics over time. This tracking helps to identify trends and to address any issues that may arise. By providing ongoing monitoring, organizations can ensure that the data in the new system remains accurate and consistent.

User Support and Training

User support and training are essential to ensure that users are able to use the new system effectively. This support should include a process for reporting and resolving data issues, as well as training for users on how to use the new system effectively. The training should cover not only the basic features of the system but also the data quality rules and the process for reporting data issues. By providing this support and training, organizations can ensure that users are able to use the new system effectively and that any data issues are addressed promptly. This support should be ongoing, with regular updates and refreshers to ensure that users are up to date on the latest features and processes.

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SysGenPro Editorial

SysGenPro Editorial

Platform & solutions team

Practical guidance on ERP, AI automation, cloud deployment and enterprise transformation from the SysGenPro team.

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Frequently asked questions

Common questions on this topic. Talk to our team for anything specific to your business.

01Why is data cleansing important in ERP migration?

Data cleansing is important because it ensures that the data in the new system is accurate, complete, and consistent. Migrating dirty data can lead to broken business processes, inaccurate reporting, and user distrust in the new system.

02What are the steps for cleaning legacy ERP data?

The steps include data extraction, profiling, cleansing, transformation, and validation. Each step requires careful planning and execution to ensure that data quality is maintained throughout the migration.

03How do you handle duplicate records during migration?

Duplicate records are handled through deduplication, which involves identifying and merging duplicate records into a single, accurate record. This process requires careful matching rules and manual review for ambiguous records.

04What tools are used for ERP data cleansing?

Common tools include data profiling tools, data cleansing tools, and data validation tools. These tools can automate many of the tasks involved in data cleansing, such as identifying missing values and checking for duplicates.

05How long does data cleansing take in an ERP project?

The time required for data cleansing depends on the volume and complexity of the data, as well as the level of automation used. It can range from a few weeks to several months. It is important to allocate sufficient time for this phase to ensure that it is done thoroughly.

06Who is responsible for data quality in migration?

Data quality is a shared responsibility between IT and business stakeholders. IT is responsible for the technical aspects of the cleansing process, while business stakeholders are responsible for defining the cleansing rules and reviewing the results.

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