by Rob Byrd and Earl Pedersen, SI International
Within the satellite industry, whether on the military or commercial side, the agency- or company-wide framework that incorporates all of the computing, information and management systems is known as the Enterprise Architecture (EA) or Solution Architecture. EA is the model for the operation and organization of a company, agency, command, and so on, as defined in various documents that deal with the structure and formation of various information systems or services. Such is commonly defined within one of the structures of the EA, that being the architecture domain. There’s business architecture, data architecture, applications architecture, and technical architecture. These cover everything from protocols, server nodes, software modularization, application interaction, data in motion and storage descriptors, business goals, and roles. A complex environment, to say the least, but one crucial to the success of any military, agency, or commercial endeavor in the satcom industry.
Which is why we’ve asked SI International (SI), a leader in object-oriented analysis and design (OOAD) application, to reveal their Unified Modeling Language (UML)-based method, Net-Centric Enterprise Architecture, which defines and models target enterprise operational processes. Such aids in facilitating transition planning to a service-oriented architecture (SOA), which brings into play interoperable services and IT infrastructure definition, with functionality grouped around business processes.
Why is SOA so important? It forms distinct services from the functions, makes all accessible via a network for merging, and reuse in business application production. Data is passed from one service to another, or an activity is coordinated between services, and the communication between the various processes exchanges the information quickly and reliably.
SI professional services include a repeatable technique to capture mission requirements in context of operational use (Requirements Understanding); to discover common, extendable, and reusable processes (Integrated Enterprise) and to assist in the implementation of target enterprise capabilities via a well-managed spiral model (Managed Change). Their EA Center of Excellence (COE) in Colorado Springs is a showcase of state of the art architecture development facilities designed specifically for enterprise model development.
SI’s object-oriented (OO) approach leads to the production of highly integrated, agile, and affordable systems, fielded in a shorter amount of time compared to the traditional structured analysis approach. SI determined after much research that UML business models used to manage functional requirements are easier to understand by business analysts and, ultimately, the developers tasked to build the systems. As the software development industry is acutely aware, the significant power of an OO approach is the ability to identify reusable elements within and among enterprises using a service-oriented architecture approach, to include:
- Processes (operational or business activities)
- System components such as enterprise workstations and servers
- Interfaces such as those between internal and external data sources
- Nodes taking into account organizational considerations
- Architectural concepts such as information exchanges
The Case for Object-Oriented UML Enterprise Architecture The UML is an industry standard for the creation of visual models that represent behavior of business systems for object-oriented software development. It combines the best diagramming practices applied by software developers over the past 40 years. The Object Management Group (OMG) formalized the notation in 1997 and the DoD community is formalizing a common UML approach through OMG’s UML Profile for DoDAF Department of Defense Architecture Framework and MODAF (United Kingdom Ministry of Defence Architectural Framework) (UPDM).
The acquisition of all major DoD weapons and information technology systems are required to develop and document an EA using the views prescribed in the DoDAF. Complete systems definitions are required by MODAF for the procurement and integration of defense systems in the UK. The entire modeling standard is known as the Unified Profile for DoDAF and MODAF, or, UPDM. The UPDM standardizes a common UML profile to ensure consistency of method and architecture data elements throughout the defense enterprise.
The UML is not a computer software language such as Java or C++, among others; rather, the UML is a visual language using semantically rich, graphical and textual design notations to capture information technology conceptual designs. The UML improves commucation among conceptual teams as the design evolves and the community reaches agreement. The language allows the reader to reason about the design. The language provides an unambiguous basis for implementation. The UML shows the essentials of the system from a particular perspective and hides the non-essential details. The following paragraphs describe an object-oriented architecture purpose and benefits.
Reduced Complexity – Object-orientation is exactly what it implies — orientation toward the object, rather than functional decomposition, which is oriented toward decomposition of functions. Objects are abstractions, a way of describing the real world by addressing the information about the object that is important to your purpose or the problem you are trying to solve. Thus, the OO modeling notations provide the architect a way of modeling important requirements, while hiding unnecessary information (such as implementation details) that can unnecessarily complicate the higher-level problems under investigation.
UML diagrams provide a foundation that allows architects to focus on differing perspectives of the solution. UML packages provide additional flexibility to segment (package) portions of the overall solution. These packages allow visionary teams to group implementations by contracts (agreements between stakeholders) while maintaining the integrity of the architecture’s desired effect.
Adaptation and Flexibility—SI’s early innovation with UML was to create UML Use Cases abstracted to the enterprise level rather than software coding level. Initially, SI used this approach to model command and control (C2) functions built once and reused (extended or adapted) many times to reducing system implementation cost. As service-oriented architectures became prevalent, SI realized their enterprise level use cases were descriptions of service behaviors and reusable in many different ways – achieving many differing effects. Just as developers were able to maintain reusable software components in class libraries to provide a system level service, SI maintained reusable use cases in a repository of business level libraries. Thus, their robust use case repositories provides agility to create new mission threads more efficiently.
Cost and Risk Reduction—OOAD goes hand-in-hand with other modern software development best practices such as visual modeling, iterative development, and risk-driven development, among others. These techniques target the well-known “IKIWISI” phenomenon in software development, that being the user who can’t quite describe their requirement, except that “I’ll know it when I see it.” This tongue-in-cheek acronym describes a very serious risk to projects—lengthy requirements evolution and meticulous software development, but when end users try the final product, they find they really wanted something different.
Discovering this disconnect late in the effort, after significant design concepts have been locked in, after significant cost has been expended, and after significant schedule has passed, can often be fatal to a project. SI believes the solution includes the development of UML Use Cases to place requirements in context; visually modeled to better communicate requirements; iterative and incremental development to capture early user feedback; and early rather than late introduction of high risk areas to accommodate change prior to significant cost and schedule consumption.
Common Language and Method—UML is an industry standard with more than 10 years of successful use. Its popularity has grown with OO development and Web technologies. Today, most computer science graduates learn the UML, staging the notation as a tremendous tool to communicate requirements between architects and developers. One of the compelling reasons for using the UML to describe an enterprise is the idea of leveraging the common notation to describe requirements from concepts to code, providing traceability from mission requirements to the implemented services. In a partnership with the MITRE Corporation, the team demonstrated a complete UML framework where use cases successfully drove software and system design (also using the UML).
Transition Planning—During software development, coders logically package elements of the architecture into subsystems or logical components targeted at providing similar functionality, and those subsystems or logical components are mapped to platforms that realize performance, availability, fault tolerance, scalability and other non-functional requirements.
At the enterprise level, after modeling a representative number of target mission threads and use cases to the stakeholders’ satisfaction, this same process of logical and physical realization can begin. However, at the EA level of abstraction, we focus on understanding how adequately current IT resources fulfill the use case requirements.
At this stage of the architecture, Class Diagrams capture required services and assist in identification of gaps in capability. Packaged in logical groups, the use cases provide a contextual understanding to determine solutions via (1) existing IT resources, or (2) new projects targeted at closing the gaps. Where existing IT resources fulfill required services, UML Deployment Diagrams capture applications and servers providing a mapping (trace) to the physical platform. Our process provides the architectural foundation to close capability gaps through well-defined prioritizations, schedule, and cost into portfolios achieving the enterprise’s objectives.
Sequenced over multiple budget cycles, well-defined capability gaps compete better in any given year for limited funds. Before commissioning actual projects, priorities must be set each year through a formal Capital Planning and Investment Control process. All government agencies have this process: For example, the DoD uses the Planning, Programming, Budgeting and Execution (PPBE) system. Figure 2 shows how EA fits into an Enterprise Management Model where the ability to provide “CONOPS-to-code” has real-world management significance.
*SWOT - Strengths, Weaknesses, Opportunities and Threats
CPIC - Capital Planning and Investment Control Some notable differentiators of SI’s enterprise architecture approach include:
Enterprise Architecture COE—SI’s Colorado Springs EA COE provides an environment where SI concentrates their expertise and centralizes support to architecture and BPR efforts wherever their clients may be located. Building a UML modeling team with the necessary skills and resources from scratch in a new location can take as long as one to two years, depending on the availability of a skilled staff.
SI’s staff includes many Senior Principal and Principal Enterprise Architects with OMG UML Professional Certifications practicing the object-oriented trade in excess of eight years. Their architecture staff currently consists of 35 trained and experienced object-oriented UML professionals, anticipated to be the largest concentration of UML enterprise expertise in the country.
As architecture is extremely collaborative, SI emphasizes facility considerations. To be successful in developing use cases, architects collaborate and mentor in architecture laboratories properly equipped with large visual displays, computers, and controlled data access points. The large displays are necessary to observe all views of the use case and the many data sources (concepts documents and other information sources etc.) sometimes used to understand the required behavior (i.e., use case description) being modeled.
Their architecture environment allows architects, subject matter experts, and stakeholders to collaborate on the architecture and agree on the optimal solution. SI hesitates to consider these architecture laboratories optional—they are so productive that they built six laboratories and they’re in regular use today.
Tools and Repositories>—SI has extensive experience building enterprise repositories, managing their configuration, and delivering their contents to clients via the web and/or on CD/DVD. They offer the use of their labs to save schedule and client investment cost. After extensive UML tooling research, they deployed IBM Rational Software Architect and Modeler (RSx) in their Architecture COE. They determined the most significant strength of IBM Rational tools is their popularity within industry.
IBM includes founders of the UML (then Rational), their tool provides a proper object-oriented implementation (another significant attribute). IBM still provides UML leadership today through the Object Management Group (OMG). In addition, SI has a strong partnership with IBM Rational; IBM recognizes SI as enterprise architecture thought leaders in object-oriented enterprise modeling and regularly collaborates with SI on tooling considerations. The use of UML stereotypes (i.e., symbols, relationships, etc.) does not necessarily mean the underlying tool storage mechanisms are object-oriented.
Scalability is important, and this is particularly true if you’re modeling complex enterprises, or you intend for your business models to go to code. Business models built using RSM are importable into Rational Software Architect (RSA), a UML tool that provides code generation. This approach allows the business model to evolve simultaneously with the implementation system model with no data concordance issues. This approach provides full traceability from CONOPS to code laying the foundation for UML models as a portfolio management and decision making mechanism.
Architecture Verification and Validation—Having standardized on the IBM Rational platform, SI built specialized plug-ins to IBM’s toolset providing capabilities found nowhere else in the industry. Their enterprise mission threads link UML Use Cases to achieve an end-to-end business process. Even with standard operating procedures in place, there is no guarantee the entire mission thread (with use cases developed by differing teams) will execute properly.
To resolve this problem, SI determined that object flow was essential for use case integration. The company built a verification tool that checks object flow within, and between, use cases through any business thread. In the Rational tool, the observer actually sees an animation of objects moving from one use case activity to another. If the animation stops, SI architects know they have a problem. More importantly, they know where to focus their corrective actions. Their tool greatly reduces architectural risk and portfolio development risk.
Another significant SI innovation is the development of a UML tool plug-in that creates 2D animations actually driven by the architecture. This validation tool plug-in allows SI to depict, visually, the mission thread in a context that users and mission executives can understand. They use these visualizations to demonstrate deployment of military resources on world maps; portray network information exchanges; and to animate business processes both within the office and beyond the enterprise boundary.
Their technique engages stakeholders because they see and understand the model they are developing, providing participation and buy-in to the requirements development process. SI architects continue this validation approach iteratively until the mission animation runs exactly as the stakeholders want it. Often, this facilitates agreement among stakeholders.
Using the integrated architecture, SI data mines their UML models to extract information to create important documentation communicating progress, areas of emphasis, development of functional requirements, as well as planning and acquisition documentation.
Figure 4 shows a PC screenshot during the execution of such an animation, where a UML model (left screen shot) of an electronic purchase order system (e-PO) is driving a 2D animation (right screen shot) of interactions across enterprise boundaries and throughout a large metropolitan area. SI International visualizations provide a simplified view the non-architect can easily understand.
Summary
SI International’s object-oriented approach to enterprise architecture provides a proven and industry-leading capability to manage today’s complex web and network-based SOA transitions. SI’s processes and tools capture all the architecture information necessary to provide a concept to code capability, including the ability to align the expectations from the highest-level executives, project managers, and developers.
Contact author Earl Pedersen
Contact author Robert Byrd