The Integrated System Diagnostic Design (ISDD) Tool Suite provides a model-based solution for all the diagnostic needs of system design, including:

• Diagnostics-Specific Analytics (Testability, False Alarms due to Diagnostic Deficiencies, etc.).
• Diagnostics-Informed Assessments for Reliability, Risk & Safety (FMECA, FTA, Sneak Circuit, etc.)
• Measuring the Impact of Prognostics upon Diagnostic Performance
• Development & Validation of Diagnostics for Production, Maintenance and On-Board Health Management
• Simulation-Based Case Studies for the Optimization of Life-Cycle Sustainment
• Full Integration of Model-Based Diagnostic Data into Standard-Based and Proprietary Digital Threads

The Big Picture

The ISDD Tool Suite is comprised of four core applications, plus a number of associated modules and auxiliary tools. This is a lot to take in at a glance, so let’s begin by focusing on four main tools.

The Core Four

Three of these are development tools: eXpress & STAGE are for diagnostic engineers, whereas the Run-Time Authoring Tool (RTAT) is intended for either engineers or advanced technical writers. The fourth tool, DSI Workbench, is designed for technicians in maintenance & production environments, as well as for on-board (embedded) troubleshooting.

eXpress – Diagnostic Modeling, Development & Analysis

DSI’s flagship tool, eXpress is an environment for the creation, validation and optimization of model-based diagnostic solutions (including system diagnostics, Prognostics Health Management, Test Program Sets and other diagnostic applications). eXpress also provides industry standard assessments of system testability, as well as diagnostics-informed Reliability, Risk & Safety analyses. (read more)

STAGE – Simulation-Based Sustainment Trade Studies

Using diagnostic engineering data from eXpress, STAGE simulates failures, diagnoses & different combinations of corrective, condition-based, predictive and preventative maintenance. It provides simulation-based metrics & graphs for Testability (including false alarms), prognostic effectiveness, Reliability, Maintainability & logistics planning. (read more)

RTAT – Run-Time Authoring & Diagnostic Translation

The Run-Time Authoring Tool (RTAT) allows diagnostic procedures exported from eXpress to be enhanced for use within DSI Workbench or translated into other formats to support customer-specific digital integration efforts. (read more)

DSI Workbench – Run-Time Diagnostic Reasoning

DSI Workbench is a turnkey (yet heavily customizable) graphic-based diagnostic executive & maintenance environment that allows diagnostics developed in eXpress to be hosted on a fielded system or deployed in a maintenance or production facility. (read more)

Modeling & Analysis

In addition to eXpress and STAGE, the ISDD Tool Suite offers a number of specialized modules that analyze the impact of the diagnostic design upon system Reliability, Risk & Safety, as well as support the development of diagnostics for two and three-tiered maintenance concepts.

FMECA Plus – Allows Failure Mode, Effects & Criticality Analysis data (either imported or developed in eXpress) to be enhanced with metrics derived from the eXpress diagnostics. FMECA Plus is automatically included with all eXpress licenses. (read more)

FTA Module – Allows eXpress to perform a Fault Tree Analysis. Fully integrated with both FMECA Plus and the eXpress diagnostics, the FTA module provides diagnostic & prognostic-informed fault trees for Risk & Safety analyses. This module is automatically included with all eXpress licenses. (read more)

Sneak Path Analysis Module – Allows eXpress to define point-to-point signal definitions and perform Sneak Circuit Analysis—identifying sneak, crosstalk and/or failure paths for those signals.

Prognostics Module – Allows eXpress to analyze the impact of a design’s prognostic capability upon diagnostic performance. Prognostic measurements defined in eXpress can also be exported to STAGE for use in maintenance trade studies. (read more)

Maintenance Module – Provides a set of features to support the linking of diagnostics in multiple maintenance levels, the creation of serial maintenance procedures (based on multiple criteria) and the static analysis of false alarms resulting from diagnostic ambiguity at the failure mode level. (read more)

Diagnostic Development & Deployment

Although DSI Workbench is the centerpiece of our run-time offerings, DSI does provide two other diagnostic reasoners, as well as several modules that support the development and deployment of run-time diagnostic solutions.

eXpress Design Viewer – Allows diagnostic engineering data to be shared and/or reviewed on systems where eXpress is not installed. This not only facilitates team collaboration, but also allows customers to examine work done in eXpress. (read more)

DSI Embedded Reasoner – Allows system developers to embed diagnostic sequences from eXpress into an integrated system health management solution. (Available as flight-certifiable source code) (read more)

DSI Dynamic Reasoner – Implements dynamic reasoning within DSI Workbench or a third-party diagnostic executive (requires the Dynamic Diagnostics Module in eXpress. (read more)

Dynamic Diagnostics Module – Allows eXpress to export the proprietary data files used by the DSI Dynamic Reasoner. This module also allows dynamic reasoning to be validated using the Desktop Fault Insertion feature within eXpress.

WB History & Feedback Module – Tracks and records maintenance actions and fault resolutions in DSI Workbench, storing the data in a standard relational database. This module also allows DSI Workbench to display empirical maintenance knowledge alongside engineering-based diagnostic conclusions. (read more)

Digital Integration

The ISDD Tool Suite offers a variety of options for digital integration. The primary formats for sharing data across a digital thread are eXpressML and DiagML. Moreover, both eXpress and DSI Workbench can be accessed remotely via their respective ISDD Modules. Data can also be stored, imported or exported using commercial formats (Excel spreadsheets, relational database, etc.), as well as special-purpose formats.

eXpressML Module – Provides the ability to import and export eXpressML data to and from eXpress. This module features a data-centric, smart import that works interactively with the user to determine how to handle situations where data is ambiguous or missing.

Design Import Manager – Software translation between eXpressML and other industry formats. Although any tool can fulfill this role, DSI currently supports two third-party tools that facilitate integration with MBSE data: ATML Pad (by Reston Software) for importing & exporting SysML from Catia Magic, and Capella2eXpress (by Spherea Test and Services) for importing from Capella.

ISDD Module (eXpress) – Allows a third-party software client to control eXpress remotely by issuing commands across a TCP/IP interface. Models can be created or updated from eXpressML and validated using both the eXpressML smart import and the eXpress error checker. For existing models, data can be exported or retrieved remotely.

ISDD Module (DSI Workbench) – Allows a third-party diagnostic executive to use the reasoning capability of DSI Workbench by issuing commands across a TCP/IP interface.

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