Model-Based Product Line Architecture and Analysis

1. Model-Based Product Line Architecture and Analysis SEDC 2014 Conference Friday, 04 April 2014 Sean McGervey Systems Architect Sean.McGervey@jhuapl.edu

2. Acknowledgements • Tamara Valinoto • Chairperson of Northrop Grumman’s MBE Community of Practice • Sounding board • Source of sustained motivation for finishing my presentation • … and Dear Friend --- Thank you!

3. Agenda • Why is a new paradigm for development needed? • Three enabling elements for the new paradigm • Model-Based Systems Engineering • Multidisciplinary Analysis and Optimization • Product Line Architecture • Rationale for combining these enabling elements? • How can these enabling elements be combined?

4. So Why is a New Development Paradigm Needed? • Product development is still often based on opportunistic reuse or one-off modification of components to fit needs • Components that are modified must go through time consuming and costly verification and validation again • New and modified components have no pedigree or usage history making them riskier to use in products • Component development often involves multidisciplinary design aspects, conflicting requirements, and management of complex sets of system attributes and their parametric relationships Product A Payload Radar Structural Frame EO/IR Engine Comms Product B Radar Payload Weapon System Structural Frame EO/IR Engine Comms

5. Enablers for a Better Development Paradigm:Model-Based Systems Engineering • Well-defined interfaces and self-consistent specifications for products and components • Robust traceability of flow down of requirements to design of products and components • Ability to assert structural, behavioral, and parametric relationships between components of products Requirements Behavior Structure Parametrics

6. Enablers for a Better Development Paradigm:Multidisciplinary Analysis and Optimization • MDAO has long been a staple of the aerospace industry • Notably, championed by NASA’s Glenn Research Center • MDAO attacks the problem of multidisciplinary system design, analysis, and optimization • Federates computational models of the system from the perspective of various design disciplines

7. Implementing a Better Development Paradigm, Part 1:MBSE + MDAO = Integrated Analytical Design Verification During Product Development, system attributes captured in the system model can be parametrically related to technical measures and analyzed by an integrated MDAO framework MBSE Workflow Integration Mechanism MDAO Workflow

8. Enablers for a Better Development Paradigm:Product Line Architecture Automobile Use Cases Kernel Use Case • Product lines enable reuse at each phase of the systems engineering lifecycle • Everything including product requirements, features, and configurations can be reused during product development • Many requirements will be common across all products in a product line, while others are optional • Key to realizing “economy of scale” benefits lies in preplanned reuse of product components <<kernel>> Brake Car <<kernel>> Steer Car <<kernel>> Start Car <<optional>> Open Roof Optional Use Case Automobile Features Common Feature Optional Feature Automobile Product

9. Enablers for a Better Development Paradigm:Product Line Lessons Learned from Lego™ • Lego™ products are not just popular for the predefined designs that can be built, but for the reusable blocks • Blocks have well-defined and standardized specifications which governs how they can be used • While an entire predefined design has limited reuse value, the blocks have tremendous reuse value

10. Enablers for a Better Development Paradigm:Reuse Should Be Pre-Planned, Not Opportunistic Failing to appreciate that can result in unforeseen time and money modifying a component to fit a new product context Reusing a component means reusing all the requirements and architectural decisions that drove its development

11. Enablers for a Better Development Paradigm:Techniques for Product Line Architecture Modeling • PLUS (Product Line UML-Based Software Engineering) • PLUS extends UML for modeling commonality and variability in software product lines • PLUS can also be used to extend SysML to model system-level product lines • System level requirements, use cases, domain features, and architecture can all be modeled as required, optional, mutually exclusive, and more

12. Implementing a Better Development Paradigm, Part 2:PLA + MBSE = Domain Specific Modeling Language • Combining PLA with MBSE allows unambiguous and self-consistent specification of systems in terms of the components that are common, optional, and variable across members of its product line • Models can be built using standardized elements that are domain-specific with rules for their use that can be validated and enforced by tools

13. Implementing a Better Development Paradigm, Part 2:PLA + MBSE = Domain Specific Modeling Language • The application of MBSE to the specification of a PLA also sets the stage for using MDAO for verifying design assertions • Parametric relationships between families of components can be specified and analyzed to guide an optimal system assembly

14. Putting the Pieces Together:MBSE + MDAO + PLA = Robust Product Development Development starts with specifying the new product in terms of the product line’s architecture constraints, and determining which components are already provisioned and which must be developed. MBSE (Product Specification) New components are developed using the domain specific modeling language for the product line, and their design is verified using the integrated MDAO framework. Verified components are added to the collection of provisioned components for the product line, and can be used in future product development. PLA (Component Provisioning) MDAO (Product Verification)

15. Summary • Products can be made faster, cheaper, and better by adopting a product line approach to their development • Opportunistic reuse and one-off modification of components is replaced by pre-planned reuse for product development • Development of new components is managed in accordance with the constraints of the product line architecture • The architecture of each component, product, and product line is specified using a SysML-based modeling language that is specific to that product line’s domain • Development of products and new components is guided by continuous verification of their design using an integrated multidisciplinary analysis and optimization framework