Since its inception in 2004, the Network Centric Operations Industry Consortium (NCOIC) has been a leading organization in promoting the value of interoperability across operational domains. Minimum Level InteroperabilityBuilding on network centric operations (NCO)1 concepts proposed for the military at the turn of the century and leveraging the value gained from effects-based operations (EBO)2, NCOIC has advocated the importance of including interoperability as a required condition in every complex problem/solution analysis for all organizations.

Interoperability has become a necessity for any organization operating on the network since it improves information sharing, which enhances situational awareness and leads to better decisions and faster responses.3 As important as interoperability has become, there are still many organizations that choose not to be completely interoperable. But how much interoperability is enough? This paper introduces Minimum Level of Interoperability as a conceptual approach to achieving the basic capability needed for a particular task or mission.

Merriam-Webster Dictionary defines interoperability as the “ability of a system to work with or use the parts or equipment of another system” (first use in 1965). Google and Bing search engines deliver the following definitions of interoperability: the ability of computer systems or software to exchange and make use of information (interoperability between devices made by different manufacturers); and the ability of groups to operate in conjunction with each other (staff believe interoperability between forces is crucial to effectiveness). In each case, the key concepts are the ability to work with or use parts of another system, and the ability of equipment or groups of people to operate in conjunction with each other.

For this paper, interoperability is a characteristic that denotes the capability to exchange and/or share information. This allows for the inclusion of human operators and automated systems, including intelligent agents (i.e., bots and robots acting as the sources and recipients of information).

Levels of Interoperability
The term “level” is frequently used in characterizing interoperability. It denotes degrees of completeness, sophistication and complexity, with higher levels associated with greater intellectual exchange. Two examples of interoperability hierarchies are Levels of Information Systems Interoperability (LISI) developed by MITRE4 and interoperability characterization known as Levels of Information Interoperability for Network Centric Operations (LIINCO) developed by Boeing and licensed to NCOIC. The NCOIC technical team, led by Thomas Bui, Ph.D., of Boeing, identified key elements needed for systems-of-systems interoperability, potential solutions and a hierarchical concept. This effort resulted in a process used by Boeing for characterizing the appropriate interoperability level for a given platform based on its intended role in the planned network centric environment. Using the LIINCO framework, interoperability requirements were mapped into five levels of increasing capability. This work led to frequent discussions regarding how much interoperability is needed and what is the minimum level one must have to participate.

Minimum Level of Interoperability
It is more correct to think of the minimum level of interoperability (MLI) as a threshold (i.e., from the perspective of defining/describing the minimum interoperability needed to get information successfully moved from Point A to Point B). This perspective was first characterized circa 2004 by Marshall (Tip) Slater, a senior executive at Boeing. Slater was responsible for planning and executing the first steps in creating a virtual organization that would operate from multiple and geographically dispersed locations and be connected by a system of communication networks. The business “use case” for this network centric organization was the development and delivery of product demonstrations involving live, virtual and constructive elements operating from multiple and geographically separated production sites. Delivery of the finished business unit product-demonstration and operator (role-playing) interactions were carried out over the open worldwide Internet and presented to the customer/audience at a designated international location of their choice -- literally “across the globe” from the production sites.

The MLI described here is not a level of achievement in the expected technical sense, with specified bandwidth and throughput capacity values. More correctly, the MLI needed represents a starting point (i.e., the threshold capability level that must be in place to claim interoperability as an operational attribute). The MLI concept evolved out of the necessity to answer the question: What is it that we must develop or assemble to make it work and perform the international demonstration? After consultation with Dr. Bui and the NCOIC technical team, the answer boiled down to satisfying three critical needs.

To claim interoperability, you must: 1) be able to communicate with others; 2) be able to digitize the data/information to be shared; and 3) be recognizable/registered (i.e., you must have some form of credentials verifying both senders and receivers on the network as authorized participants with specific roles).
Simply stated, for MLI, you must be able to communicate, digitize and register. But there is considerable detail needed in completing the paths through these three requirement areas. And the execution process applies for each interoperability level defined for the intended system.

  • Communicate
    • Able to find and join the network; this requires compatible, physical communications capability and access to the correct network(s)
    • Able to discover, acquire and communicate (send and receive) with other compatible participants acting as both information sources and recipients
    • Able to secure the physical transmission of information
  • Digitize
    • Network centric operations require all data to be in the binary (0,1) digital format.
    • Information received from analog sensors must be converted (digitized) into the digital format required for network communications traveling at near the speed of light.
    • Ensuring the authenticity of readable, recognizable and uncompromised data/information must be part of the digitization process and methodology used at all nodes on the network.
  • Register
    • Entities must identify themselves through a process or service that provides confidence regarding their authenticity and authorization to send/receive and produce/modify data.
    • Entities must adopt and share a common governance policy and methods for authorizing and documenting the exchange of information and actions taken, and a way for determining who’s who in the network.
    • Managing registration in a rapidly expanding, federated environment will always be a challenging problem as the number of nodes participating multiplies; fortunately, many new ways for doing this are evolving.

The challenge for those responsible for implementing an interoperable solution is that they are not the sole authority or ultimate decision maker; their success will depend on the social interoperability and cooperation of others in a federated environment; the decisions made must have the endorsement of all participants in the group or interoperability fails.

The program manager must put in place the process and capability to identify and define what’s needed to complete the information transfer path, work through the three MLI key areas (communication, digitization and registration) and overcome any obstacles to integration identified in the NCOIC paper describing the NCOIC QuadTrangle™.5


The program team will need to complete a thorough analysis of the mission objective, working environment, participating parties and all proposed alternative solutions, including existing capabilities and available resources, to determine:

  • Is everyone on the same network or are multiple networks using different transmission mediums necessary to span the geographical areas? Are there appropriate gateways and transformers in place to connect all participants?
  • Is everyone using the same methodology for digitizing data and sharing information? Or is there confusion caused by use of different forms, semantics and languages?
  • How many different registration processes and methodologies are being used to address the most challenging and critical issue? Operators in the network must be able to know and trust each other and have the security needed to provide appropriate protection of the information shared.
  • What are the minimum conditions necessary to be able to interoperate with others at each of the designated levels, zones or degrees? What is the interoperability starting point that every participant must achieve before they can claim interoperability at their designated position and role in the operational environment?

Success in applying the MLI concept to achieve interoperability will be directly proportional to how well the final choice of alternatives measures up in satisfying the four keystone interoperability dimensions identified in the NCOIC QuadTrangle™.

By Edward L. Barger
NCOIC Technical Director



1 Alberts, David, Garstka, John, and Stein, Frederick, Network Centric Warfare, Developing and Leveraging Information Superiority. Washington, DC; CCRP. 2000, 2nd Ed. Revised
2 Smith, Edward Allen, 1946-. Effects Based Operations: Applying Network Centric Warfare in Peace, Crisis, and War   - Air University

3 Network-centric warfare – Wikipedia, the free encyclopedia
Network-centric warfare, now commonly called Network-centric operations;  Developing and Leveraging Information Superiority.

4 Measuring Systems Interoperability - Software Engineering Institute  Levels of Information Systems Interoperability (LISI) is a reference model and process for assessing information systems' interoperability. It provides a discipline for defining, measuring, assessing, and certifying the degree of interoperability required or achieved between systems.

5 NCOIC QuadTrangle™ The Four Interdependent Dimensions of Cross-Domain Interoperability