Understanding QSLS Architecture Tool: Inputs and Outputs

When dealing with stakeholders, QSLS provides Clear Measurements to describe your system solution

The Quantifying System Levels of Support (QSLS) methodology has emerged as a powerful approach to system engineering, bringing quantitative rigor to architectural evaluation. The QSLS Architecture software tool implements this methodology, enabling architects and engineers to measure how well a system architecture supports quality attributes and business drivers. Let's explore what goes into this tool and what valuable outputs you can expect.

Essential Inputs for the QSLS Architecture Tool

1. Architectural Mechanism Selection

The foundation of QSLS analysis begins with identifying which architectural mechanisms are present in your system. The tool requires:

• A list of selected architectural mechanisms from the QSLS Book of Knowledge

• Weight values (0-1) for each mechanism indicating its importance to your architecture

• Selection of the architectural viewpoint to be analyzed (functional, operational, security, etc.)

This input establishes the baseline understanding of what your architecture consists of and how those elements relate to the viewpoint under analysis.

2. Standards Information (Optional)

If your system adheres to specific industry or organizational standards, the QSLS tool can incorporate this information:

• Selected standards from the QSLS standards database

• Weight values (0-1) indicating its importance to your architecture

Each standard will identify a set of mechanisms and weight values for the mechanism (related to importance of the mechanism to the standard).  The user can modify the weight value as needed (especially if the mechanism has other uses in the system). Standards integration helps ensure your architecture meets necessary compliance requirements while supporting quality attributes.

3. System-of-Systems Definition (If Applicable)

For complex systems comprised of multiple subsystems, the tool requires:

• Identification of constituent systems

• Weight values for each system's importance within the overall system-of-systems

This information enables the tool to evaluate how individual system contribute to the overall system-of-systems quality and business drivers.

4. Quality Attribute Priorities for generation of Business Driver weights

To align the analysis with stakeholder priorities, the tool needs:

• Rankings of quality attributes (1-N) based on stakeholder preferences.  These will be converted to a set of weights for the quality attributes being applied to the Business Driver computations.

These priorities will influence how the tool evaluates the overall effectiveness of the architecture in meeting business needs.

Valuable Outputs from the QSLS Architecture Tool

QSLS provides the raw data (0-1) for the engineer to use as needed for further analysis.  In addition, a value related to a level of basic positive correlation is computed and converted to a percentage (%) to help understand where support exists vs. areas of concern can be identified.

1. Characteristic Support Analysis

The next level of outputs includes:

• Support values (0-1) for each system characteristic

• Visualization of characteristic support levels

• Identification of gaps in characteristic coverage

These metrics enable architects to understand how well their architecture supports key system characteristics.

2. Quality Attribute Support Metrics

Perhaps the most valuable outputs are:

• Quantitative support values (0-1) for each quality attribute

• Visual comparison of quality attribute support against stakeholder priorities

• Gap analysis highlighting quality attributes that need additional architectural mechanisms

These metrics help ensure the architecture will deliver the qualities stakeholders care about most.

3. Business Driver Alignment

The highest level of analysis provides:

• Support values (0-1) for each business driver

• Weighted business driver support based on quality attribute priorities

• Visualization of how architectural decisions impact business outcomes

This output directly connects technical architecture decisions to business value, helping communicate architectural choices to non-technical stakeholders.

4. Comparative Analysis

When evaluating multiple architectural alternatives, the tool provides:

• Graphical Side-by-side comparison of different architectural approaches using the average computed output for each of the architectural alternatives

  • Characteristics are compared graphically

  • Quality Attributes are compared graphically

  • Business Drivers are compared graphically

This capability supports data-driven selection between competing architectural options.

Conclusion

The QSLS Architecture tool transforms traditional qualitative architectural evaluation into a rigorous, quantitative process. By inputting information about your architectural mechanisms, standards, system components, and quality priorities, you receive valuable metrics that demonstrate how well your architecture will support both technical quality attributes and business objectives.

This approach bridges the gap between technical architecture and business value, enabling better communication between technical teams and stakeholders. The tool's outputs provide concrete evidence for architectural decisions and help identify potential issues early in the development lifecycle, when changes are less costly to implement.

For system architects and engineers seeking to improve their architectural practice, the QSLS Architecture tool offers a powerful means to move beyond intuition to data-driven architectural decision-making.