Concept Methodology

A Note To The Reader

This text describes the purpose of concept methodology. Thorough concept development is a fundamental capability and a prerequisite for developing future military operational capability. Concept development is an iterative process in which one identifies and develops future-oriented concepts to test their validity and feasibility.

Concept studies are generally carried out by a small group of highly experienced people who conduct studies of possible system ideas. They assess which preparations are necessary for product development and discuss a number of other important considerations that would affect any continued development work.

The timeframe for concept work can vary from about a year to several years, depending on the extent of the development work.


Well-implemented concept studies conducted in a short space of time at the beginning of a development programme create opportunities to greatly reduce risks throughout the entire development programme.

The products to be developed will have very long life cycles, with 30 to 50 years not being uncommon. The products must provide good flexibility and opportunities for further development throughout their life cycles.

Recommended reading

The author recommends the following texts that relate to this story: In chapter Creating value for customers under the heading Development of Technology Demonstrators in chapter Having a low life cycle cost under the heading Systems Engineering and in chapter Ensuring long-term operations capabilities under the heading Capability Development in an International Environment.

This text concerns the highlighted areas of A Journey of Change in the Aircraft Industry


The two primary purposes of concept development are to engage the customer and the market and to use increased understanding to reduce the risks associated with the development, production and operation of the product.

Since aircraft systems take a long time to develop and are to be used for several decades, the need to identify requirements is of the utmost importance. A number of stakeholders are associated with the development and further development of aircraft systems. The core stakeholders are those who are going to finance, own and use the system, that is, society, the customer and the user. An important part of concept work is supporting the dialogue with stakeholders by analysing and providing feedback on their queries.

Thorough concept development is a fundamental capability and a prerequisite for developing future military operational capability. Conceptual aircraft system development is an ongoing activity at Saab. Operations identify future market needs and review trends in tactical and technical developments. This also further develops the company's expertise and capability in aircraft system analysis.

Aircraft systems are highly complex, which means that the development of new systems places great demands on expertise in and support for describing and analysing tactical and technical solutions. The work is iterative and divided into several stages in order to increase system solution maturity relative to the need for which it is being developed, but also the need for further development as new opportunities present themselves as the concept grows. This is why the work is conducted in teams comprised of usage analysts and technology developers.

The maturity process in a concept study is divided into several stages. The initial stages aim to expand the design space/solution space to find the optimal solution. The analysis must be conducted by experienced analysts at a high system level to keep costs down.

The main aim of the final stages is to offer a robust system solution, which reduces the risks associated with the development and use of the future product. This sets demands for an in-depth analysis, as the results are used as a foundation for the agreements entered with the customer.

Important issues to communicate in concept work are expected benefits, usability and financing for developing the concepts and future products.

Content outline

  • Thorough concept development is a fundamental capability and a prerequisite for developing future military operational capability.
  • It is essential to analyse which restrictions apply in the shape of the available funding and the application area that the customer has indicated.
  • Concepts and concept design are used for a number of different purposes where a functional and physical objective has been established.
  • The starting point for a concept study is most often a life-cycle perspective. One must have a holistic perspective of the customer's operational requirements.
  • When developing future systems, one must understand the systems' potential characteristics and capabilities and discuss them with customers and/or prospective customers in possible markets.

Why Work With Concepts?

Thorough concept development is a fundamental capability and a prerequisite for developing future military operational capability. Concept development is an iterative process in which one identifies and develops future-oriented concepts to test their validity and feasibility.

Concept development serves two main purposes. One is to engage the customer and the market. The work enables the evaluation of different operational conditions, technologies, concept ideas and other data. This aids discussions about the need for and benefits of a new or refined product. The other purpose is to reduce the risks associated with the development, production and operation of the product.

When determining which material to use as a basis for concept work, one initially carries out general analyses and gathers data. The primary need is to compile market and customer needs. One also needs to consider which alternative solutions the market offers that fulfil the customer's needs.

Concept studies are generally carried out by a small group of highly experienced people who conduct studies of possible system ideas. They assess which preparations are necessary for product development and discuss a number of other important considerations that would affect any continued development work.

Concept work can be completed in a shorter period of time if it concerns changes to existing products. More extensive product changes or completely new products entail concept work that takes a long time. The difference in time is due to the fact that new products demand much broader studies as regards use and technology.

Identifying solutions and risks

Well-implemented concept studies conducted in a short space of time at the beginning of a development programme create opportunities to greatly reduce risks throughout the entire development programme.

Saab often has development programmes that can run from 10 to 15 years. Our experience shows that the total cost risk during the development phase can be more than halved with well-implemented concept studies. This underlines the importance of conducting structured concept work before starting any extensive systems development.

The products to be developed will have very long life cycles, with 30 to 50 years not being uncommon. The products must provide good flexibility and opportunities for further development throughout their life cycles, so consideration must be given to altered customer needs as well as new technical possibilities. The benefit to society will be seen for decades. It’s not the development projects budgets that are affected. It’s the governmental budgets.

Concept studies provide considerable contributions to political preparation. This is not only information from company to the government, it is also contributions in the internal governmental process. Long-term approaches to benefit analyses and practical planning are musts in larger procurement processes. One must also conduct extensive, long-term evaluations of the benefit to society. The coordination of requirements and requests from the different stakeholders during preparations is a complex issue and often results in lengthy negotiations and increased risks, both financial and technical. Concept study results facilitate an understanding of the operational benefits, as well as contribute information to risk assessments.

Concept development stages overview

The figure above illustrates the different product development stages with a focus on four stages of the role of concept development in technical development.

Each stage is iterative and affects both earlier and later stages, which means that reiteration is more the rule than the exception. In order to reduce the risks of major changes during the systems development stage, it is extremely important to assess the suitability and robustness of the design. This is done in conjunction with the production of the initial concept ideas that result in the defined product.


The importance of early analyses

In the early concept work, before the product definition is established, it is relatively inexpensive to change proposed solutions and the design is open to changes. As the work approaches a product definition, a large number of people are involved in the development work and the freedom to make changes is greatly limited.

The graph below illustrates an example of the relationship between the opportunity to change the design and the accumulated product development costs. Here one can see that there is much to be gained by reducing the risks early in a product development project.

Concept growth over time

The number of degrees of freedom in the illustration corresponds to the number of alternative solutions that can be chosen. The curve representing the number of degrees of freedom shows that the design of the new product is determined relatively early in the development work. The curve representing the accumulated costs shows that early use of effective methods and tools for assessing the suitability and robustness of the design are very important.

The relationship between the opportunity to change the design and the accumulated product development costs means that it is of the utmost importance to have great expertise in systems development, as well as effective tools for assessing the suitability and robustness of the design when producing the initial concept ideas.

Methods for a holistic assessment of the concept need to be continually developed. Computer-aided integration is required so that the different stages can use shared models for developing and evaluating the concept ideas. Identifying risks, proposing measures and developing alternative solutions are important tasks prior to finalising the product definition.

The design can be analysed using simulations, prototype development and prototype testing. These activities are begun during the concept phase and continue thereafter alongside serial development. This greatly reduces the risks throughout the remaining development work, as well as during the production and use of the product.

Conditions – What Must Be Understood

It is essential to analyse which restrictions apply in the shape of the available funding and the application area that the customer has indicated. Moreover, the applicable political landscape and direction must be assessed, which is often decisive to being able to identify the conditions and opportunities of a business deal.

One must have a basic understanding of the environment and the context in which the product is to be used and which restrictions are associated with that use. Operational descriptions of the customer's use are crucial to gaining this basic understanding of the customer's needs and for conducting an effective analysis.

Concept development comprises technical support in marketing campaigns and a basis for negotiating and pursuing partnerships. Increased internationalisation and more close collaboration projects demand concept development that delivers financially sustainable solutions, with the opportunity of realisation in cooperation with other parties.

Understanding the customer's operational requirements – what is to be accomplished?

Good operational descriptions from customers, state authorities, users and other stakeholders are central to concept work. It is essential to understand the intended use of the product, the conditions under which it will be used and the requirements as regards characteristics and functionality. The following description refers to the stages in Concept development stages overview.

Stage 1 – Primary needs

The basis for the development work is an understanding of the perspectives defined by the principle stakeholders. The most important perspectives are as follows:

Society's needsDefence framework based on society's needs

The procurement of the type of complex systems that Saab develops shall cover the needs that society's elected representatives have assessed to be sufficient for its defence capability. This assessment is often based on a financial level balanced against society's other needs. As a company Saab can contribute by delivering solutions that offer long-term sustainability and counteract an escalating development of the system's life-cycle costs.

Customer needsthe procuring authority

The authority/customer is responsible for describing the operational requirements. The operational description comprises activities in peacetime as well as operational decisions in crisis and war scenarios. This means that the operational requirements must include different types of capabilities over a long time, some 30 to 40 years. One concequence of this is that the system must be designed from a sustainability perspective, in addition to the performance required in the most demanding crisis and war scenarios.

It is common for the authority/customer to want to coordinate the procurement process by signing agreements with several suppliers for the different parts of the system. One reason for this is to ensure the delivery of particularly important parts, even after the system is commissioned. However, a recent trend is to assign one or more system suppliers this responsibility.

User needs – using the product

Understanding the customer's operational requirements and practical use of the product is essential. The optimal solution is often a system combination that offers high performance and low costs. The performance-oriented development demands knowledge of the tactical loop, which comprises all activities to plan, execute and evaluate different specific missions.

The cost-oriented development requires knowledge of how life-cycle costs are to be balanced between the development, production and operation of the system. This requires a goal shared by the producer and the customer in order to achieve an effective industrial capability, as well as a concept that delivers effective maintenance solutions for the product over time, with spare parts provision, personnel training and so on.

Stage 2 – Operational analysis

The aim of concept work is to for a relatively low cost and with reasonable certainty propose a system solution that fulfils the customer's needs, as well as the work and resources that the supplier needs to implement in order to realise and maintain the system solution.

The work begins by understanding the customer's operational requirements and how they affect the product to be offered. Achieving understanding between the supplier and the customer requires the relatively early establishment of an objective for the technical system solution. Long before the operational requirements are agreed with the customer, work must begin on the design of one or preferably several system approaches.

The operational conditions proposed via needs analysis, scenario descriptions and tactical/technical mission descriptions, Concept of Operations (CONOPS), are compiled in an Operative Concept Description (OCD). The OCD must be developed in symbiosis with the development of the design solution. The analysis and establishment of tactical/technical interaction requires an iterative working procedure.

The reason is that one must understand the types of missions to be conducted, the possible tactical setup of the missions, the technical support required by these tactics and the information and data required to conduct the missions. At this early stage there are no complete concepts; instead one uses, for example, generic system approaches based on experience gained from studies of similar situations.

Other conditions that are important to define include the level and complexity of the techniques and technology that are to be used in the product. This provides input data for the requirements for technical development, systems development, production and maintainability. One can also set requirements for innovative solutions and requirements for a maturity process for the technology to be used. There are also a large number of boundary conditions to consider, examples of which include those for costs, environmental requirements, service life and the customer's existing systems and infrastructure.

Stage 3 – Concept design

Once one has a rough idea of stakeholder needs and requirements, increasingly detailed solution proposals are developed for the task of the technical system. Initially, one analyses the functions that the system needs to perform its task. This analysis leads to the transformation of customer needs and requirements into technical requirements and descriptions, which provide a basis for producing the physical solutions.

As highlighted earlier, this work is also dependent on iteration based on the operational analysis. The increasingly detailed solution proposals must be constantly compared to the operational function, which can lead to changes in both tactical and technical requirements.

Once the concept is sufficiently mature, studies are conducted on how the system should be realised within the concept work. One considers issues concerning what to develop in-house and which off-the-shelf solutions to procure externally. One also analyses possible collaborations with different types of partners and suppliers. The latter issues are most often determined by business and contractual conditions.

Stage 4 – Product definition

The final concept stage involves compiling the conclusions of the operational analysis and the concept work into a product definition. This provides a basis for the agreements on the procurement of the new system.

Conducted analyses and evaluations result in a synthesis that is described in the final OCD and concept descriptions that express the technical requirements prior to contract signing and serial development. These results even include a description of what the operational mission is to accomplish and how it is to be achieved with the aid of available resources. Such requirements concern, for example, maintainability, planning, education and training.

The final documentation from the concept phase then provides a foundation for planning the technical serial development and production of the system. The described concept development is recursive, that is, it will be repeated during serial development, but at subsystem level.

Concept Design – What Is To Be Communicated, What Is To Be Understood

Concepts and concept design are used for a number of different purposes where a functional and physical objective are requested. For example, when communicating with customers prior to a business agreement, the concept work and its solution proposals comprise an important means for understanding and communicating ideas and needs. Needs can be internal or external.

One example of an internal need is when management is to evaluate different business models and partnerships. Development within the existing portfolio and the development of new product ideas are examples of internal needs too. Within the technical disciplines, internal concept work is also valuable for expertise accumulation and capability development.

External needs include, for example, idea development and risk reduction related to business contracts. Saab participates at both national and international level in technical capability development and in a supporting role in analyses of issues concerning infrastructure and operational matters.

The results of concept work can be presented in many different ways, from text-based system descriptions to various types of virtual or physical technology demonstrators.

Practical concept work – demonstrate capabilities with future insight

A technology demonstrator is a prototype that with various restrictions demonstrates a possible technical or operational capability. A technology demonstrator is often created to test new limits for technical solutions, as well as to position oneself as an interesting supplier and partner. Other reasons include testing market and customer reactions to possible technical solutions to operational needs. Within the company, technology demonstrators are extremely valuable for developing new technical capabilities, as well as new organisational capabilities for more efficient and streamlined working procedures.

Developing functional demonstrators is even a common way to successively reduce risks in a project.

TRL scale means technical capability is measured in part as the capability to fulfil the needs for which the technology is intended and in part as how ready it is for use.

  • TRL9 Actual system proven through successful mission → R&D.
  • TRL8 Actual system completed and qualified through test and demonstration. → R&T.
  • TRL7 System prototype demonstration in operational environment.
  • TRL6 System/subsystem model or prototype demonstration in a relevant environment.
  • TRL5 Component and/or breadboard validation in a relevant environment.
  • TRL4 Component and/or breadboard validation in laboratory environment.
  • TRL3 Analytical and experimental critical function and/or characteristic proof of concept.
  • TRL2 Technology concept and/or application formulated.
  • TRL1 Basic principles observed and reported.

Technology demonstrators are often presented at various stages of maturity in the ongoing technical development, and examples of demonstrators are descriptive models of the future solution. They can range from a simple geometric model that can be shown on a computer to full-scale, airborne systems. Examples of such airborne technology demonstrators that Saab has produced over the past fifteen years include Filur, Shark, Neuron and Gripen Demo. (These technology demonstrators are described under section  Development of Technology Demonstrator).

Technology development and the implementation of new technology do not only take place during the development of new products, but rather continue far into a product's life cycle.

Concept content – operational solution

The operational concept includes the stated objectives of the system, as well as strategies, tactics, guidelines and limitations that affect the system. There are many other considerations that are of interest, and these may concern use and maintenance, the leadership of operational interventions and cooperation on a general level, such as between different customer, user and other organisations.

Boundary conditions always apply, and may comprise specific responsibilities and rights, how these are delegated and how operational processes are to be used to put the system solution in an operational context. The operational concept also includes demonstrating processes to initiate, develop, commission and maintain the system solution.

Concept development phases – how things are done

The idea of conceptual development can be interpreted in many different ways. According to Saab's technical development process, a concept is a life cycle stage that is introduced early in the life cycle and is used as an exploratory phase prior to serial development.

Concept development at Saab is comprised of three sub-steps, namely needs analysis, concept exploration and concept definition.

The life cycle stages are recursive, that is, they describe a working procedure that is repeated several times in a development project. The recursive flows are generally considered a hierarchic breakdown of the system into subsystem levels, with concepts created for each node of each leg of the breakdown.

The figure shows how recursive flows can be considered a hierarchic breakdown of a system into subsystem levels.

The recursive flows can even be dynamic, with concept maturity successively developing until sufficient maturity for a product definition is reached. The dynamic recursive working procedure for a product concept can be likened to increasing maturity for technology that is, increasing TRL (Technology Readiness Levels).

Studies prior to subsystem development and trade-off studies for analysing the effects of different solution proposals on the system to be developed are conducted as concept studies throughout most of the serial development phase.

In systems development one takes into account the need for access to specific expertise and a number of other resources over time. One needs well defined working procedures and a large number of tools to conduct development work, which can cost vast sums of money. The figure below illustrates the principle stages of concept maturity and an estimation of the resource growth required over time (compare with the figure for concept growth over time). The stages of maturity are described in greater detail in chapter 4.

The figure illustrates the stages of concept maturity and resource growth

It is particularly important to begin on a small scale, with different types of concepts to understand the requirements and possible solution proposals. Conducting this work in a rational manner requires a well-structured working procedure during the concept phase.

Maturity Ladder During Concept Development – How Can One Increase Understanding?

The starting point for a concept study is most often a life-cycle perspective. One should have a holistic perspective of the customer's operational requirements and one needs to reason strategically as to which technologies will be available during the product's life cycle. Naturally, this is very difficult, perhaps even impossible.

One aid, however, is to try to create foresight and a well-considered system as regards product and information architecture. One should try to create system thinking that uses interchangeability to handle changes over time.

This also means that in the initial stages one must use people who are generalists with extensive experience of concept work and product development. They are to make rough assessments of needs and propose solutions with little time invested. The analyses shall focus on the capabilities of the overall concept; the whole of the concept; complete solution; complete system and system performance – weight, drag, power, balance and other aspects that need to be predicted. Relevant risk assessments tied to the choices that are made must be made early.

The aircraft system's primary functionality must be analysed more carefully, in order to increase confidence in the initial work. The components that primarily affect the aircraft system's performance are studied in greater depth. Important considerations often include the landing gear, the fuselage and its aerodynamics, installation access and the choice of engine.

Once sufficient robustness has been achieved in the initial analyses, more in-depth analyses and analyses of subsystem plans can be conducted. Just as before, the primary functional parts should be the focus, and as the concept work progresses efforts are increased in terms of both time and resources.

Quick, short studies – reduce risks

Quick, short studies are necessary to reduce risks. It is easy to underestimate risks in new technologies and one needs to weigh things up against the overall concept; the whole of the concept; complete solution; complete system and the operational reality. One must assess the benefits and difficulties of integrating new technology, such as propulsion or navigation. One also needs to assess requirements for signature measures, fuselage structures, installations and so on. These requirements cannot be fully evaluated unless vehicles are scoped from the start for the conditions dictated by new technology.

Continuous quick, short studies is a condition to maintain competence and a knowledge bank, a library, with initial information for usage in marketing and new concept studies Needs analysis.

More in-depth concept studies include more extensive needs analysis, which encompasses how different components can or need to be adapted/tailored to system requirements and system solutions. The results of a needs analysis can comprise a basis for a decision on whether to conduct a study of a product idea.

As an example, a concept can be developed to match an aircraft to specification requirements such as aeronautical performance, signature and so on. On the other hand, initially there is no need to define all elements in detail, such as sensor integration and installations, but one ought to take into account characteristics that determine the concept's size and capabilities. Examples of these characteristics are the weights, volumes and power needs of all systems and components.

The analysis includes integration studies of equipment in existing aircraft concepts. These integration studies aim to explore the effects of installed systems/equipment, or the effects of new technology.

The studies can return many different outcomes and can also concern different areas that affect flight characteristics, such as aeronautical analysis data, weight, volume, power and signature.

The results can also concern design and production issues, such as installation possibilities and CAD models. In certain cases the results lead to proposals for configuration changes to existing concepts.

As a final step in the needs analysis, an evaluation of and feedback regarding vehicle specifications fulfilment are finalised before the next concept level begins.

Concept exploration

If a decision is made to continue with a concept exploration of a product then high-level requirements are defined for systems and components, the results of which can comprise a basis for a study of a preliminary business concept.

A concept exploration entails a rough filtering of concepts or layouts. This is where the real work begins to establish requirements for the aircraft. The entire aircraft is reviewed piece by piece to see how each aspect affects the design. This is an iterative process in which functions/requirements are balanced up against costs and risks.

The concept exploration results in draft proposals for both the product and project specifications. The project specification contains the necessary data for deciding whether to continue the study.

One also develops a support and maintenance concept to analyse the product's upkeep, and the results include a cost estimate for the product and project, including risk identification.

As a final step in the concept exploration, an evaluation of and feedback regarding concept specifications fulfilment are finalised before the next concept level begins.

Product study

Choices that lead to continuing with a product study are often based on strong market interest in the concept ideas developed in the earlier stages. As the cost of a product study increases dramatically compared to earlier stages, external funding is often involved, from either a customer or other stakeholders. They can, for example, finance more extensive technical studies or the development of demonstrator programmes in order to reduce risks prior to product upgrades or the procurement of completely new systems.

The analyses conducted in a product study are similar to those in the previous stage, but are much more detailed. Now is also the time for more in-depth analyses of the development project's implementation, the manufacture of the proposed product and the conditions for using the product.

While the earlier stages are often internal preparations, the product study is generally performed together with external stakeholders. Technical institutes, suppliers and partners are examples of stakeholders, while naturally financiers expect to participate.

This stage of maturity often requires cooperation with external resources as well, to fulfil capacity and expertise needs. At this stage there is often too little certainty about closing a deal to form a development organisation, while simultaneously a technical analysis is to be conducted at a more detailed level and this requires a larger organisation and increased capabilities.

Demands for special analysis methods and facilities also require external participants. Examples include wind tunnels, climate chambers, test facilities, such as for engines, and facilities for conducting demonstrations at partners and suppliers.

Product definition

If a decision is made to continue with a concept definition of the business concept, a highly detailed product study is conducted. This defines the requirements for the system and its component parts, as well as the system's support and maintenance needs during use (ILS concept).

One also defines high-level requirements for components and subsystems, and conducts studies of different types of interfaces. A draft production plan and an outline of the production system design are also included in the concept definition. Moreover, customer requirements, desirable capabilities and all operational requirements comprise the conditions included in the concept definition.

The result of the concept definition is a collection of all development-driving technical requirements in the shape of system and subsystem specifications. In addition, there is now a well-founded concept for the maintenance system with operation and maintenance profiles established in agreement with the future user.

A draft certification process for the intended product has also been specified, and the results should include a basic configuration defined and refined for one or two different product alternatives. This basic configuration includes information about a number of different areas, such as layout (geometry), structure, sensors, antenna and armament integration, signature and so on. Some type of ground station may also be defined, in a preliminary version.

The results include a number of specific assessments of different systems and functions. One ought to at least have conducted an aerodynamics simulation for a possible configuration of the product, with preliminary data covering, for example, engine performance, mass data and aero data.

Other technology areas that must be defined are control systems, system functions and architecture. Moreover, there must be draft concepts for all supply systems in the aircraft, such as landing gear, fuel, electrical power and so on. Overall assessments and analyses should be available for durability and tactical resilience, that is, how robust the aircraft system is when exposed to damage and the loss of some functionality.

Other more general issues included in the results are cost predictions and risk assessments for the development work and the developed product. A proposed project specification for the next stage of the development work, as well as an assessment of critical time lines, should also be included if the project is to be realised.

Concept Work Example

When developing future systems, one must understand the system's potential characteristics and capabilities and discuss them with direct customers and/or prospective customers in possible markets.

Concept work is steered towards variable objectives and needs to be continually evaluated and reviewed, with the evaluation based on the described method of use. The evaluation of requested aspects is conducted in collaboration with the concerned stakeholders.

Briefly exemplified below are a few examples of possible reasons and reasoning during the early development phase. The examples comprise two different types of concept work. The first example is work based on an existing product, the Gripen, which must meet market needs and concerns further development. The other example describes issues concerning the handling of concept work for a new military aircraft system.

Concept study for the further development of the Gripen

Before the further development of the Gripen began, a number of concept/trade-off studies were conducted to assess the opportunities and risks associated with different ideas for reaching the development goals.

Common to all the studies was to retain the functions and characteristics comprising the design behind the basic Gripen system concept. Important design aspects included a simple maintenance system, reduced life-cycle costs and improved pilot support. The existing Swedish roadside base system was a cornerstone in the Gripen's development. It influenced the Gripen's performance, robustness and life-cycle cost.

In addition to performance requirements, the basic concept of the Gripen system also had objectives that aimed to reduce system costs. The latter was considered a decisive factor in the Swedish Armed Forces' opportunities to invest in and maintain a new system. Size and flexibility were considered centrl issues in restricting procurement and operating costs.

In order to proceed with further development while retaining the basic idea behind the Gripen system, a number of concept studies were conducted. The aim was to find solutions that matched market demand for greater power and longer range. The studies were conducted with a focus on engine replacement and increased internal fuel capacity.

A number of these studies concerned solutions that used conformance fuel tanks outside the existing fuselage, which would fulfil the demand for increased fuel capacity. The studies explored the placement of the fuel tanks on both the belly and the back of the aircraft. However, externally mounted tanks do not only offer opportunities, they also act contrary to some of the requirements for the new solution.

Consequently, some of the continuing work was focused on finding solutions with internal fuel tanks that did not increase the aerodynamic surface as much as an externally mounted tank. Several alternatives were studied with solutions that increased the internal fuel capacity. These alternatives entailed a smaller relative increase in drag than if the fuselage was designed with externally mounted fuel tanks.

The figure illustrates two proposed tank placements

The solution that was finally chosen meant that the main landing gear was moved from the body to the wing, which made space for a centrally located fuel tank. This enabled the fuel tank to be placed near the centre of gravity, which is an aeronautical advantage.

The figure illustrates the chosen principal solution for the Gripen E

The conclusions from the studies as regards the new placement of the fuel tank were as follows:

  • Main landing gear moved to the wing, enabling a large internal tank volume.
  • Permits increased internal fuel capacity without balance problems.
  • Entails only a minimum of structural changes.
  • Internal placement minimises drag.
  • Increased flexibility for munitions
  • Best solution for the aircraft's future development.

The studies also included solutions in other areas that motivated the further development of the Gripen system being marketable. Once a commercially sound solution had been identified, additional detailed studies were conducted for various subsystems, enabling modernisation and capability development. The later concept phases also saw the development of an airborne demonstrator (Gripen Demo) to support the evaluation, development and marketing of the Gripen.

New development study

When developing a completely new system with several unknown factors, it takes a long time before descriptions of its use and design reach the same maturity as an existing system.

Aspects that contribute to the difference in development time largely comprise how well market and customer requirements are studied and compared with trends in future technical and technological developments. There is good reason to conduct careful analyses to assess which direction to take in business and product planning.

Initially, the concept work largely involves studying and confirming future requirements together with customers. Establishing this work among the primary stakeholders is a central issue in being able to understand the actual requirements for the future system.

In turn, these requirements are driven by political, economic and technical developments in the environment in which the system is to operate. This makes the work multi-disciplinary and dynamically iterative, with converging maturity development a desirable quality.

The development of the use description is achieved through tactical/technical concept work against the background of different possible development scenarios. This means, among other things, that one must compile technology trends, linked to the described capability requirements, as described in section Quick, short studies. Each evaluation leads to the scenarios, tactics and system concept maturing, thereby increasing the level of detail.

The technical maturity is driven by studies on technologies and system solutions that cover the assessed capabilities, and these can be existing or new solutions that are combined in various ways. An important part of the concept work is defining how all the solutions are to be integrated.

The ongoing study on future military aircraft systems includes annual evaluations of the proposed system solutions.

Each evaluation cycle includes an iterative process that entails an initial synthesis, a needs analysis and a concept definition. These evaluations of future application areas and technical concepts are conducted in collaboration with, among others, military academies, research institutes and technology development companies.

As described earlier, the aim of each evaluation cycle is to increase the maturity of the operational descriptions and the technical concepts, with each evaluation cycle providing increased maturity and an increasing TRL.

In the ongoing work on future military aircraft systems, on the TRL scale the first evaluation cycle corresponds to having conducted level 1 of the TRL scale, Basic principles observed and reported, and level 2, Technology concept and/or application formulated.

The continuing work in the study on future military aircraft systems will increase the TRL in each evaluation cycle (needs analysis and concept definition), to finally reach the highest concept level, which is level 6, System/subsystem model or prototype demonstration in a relevant environment. At this stage, the concept work is completed and is followed by systems development work.

The results of the concept work are compiled in an OCD, a description of the system in its operational environment. The OCD includes descriptions of agreed needs and usage conditions throughout the system’s life cycle. Included are also tactical/technical requirements and limitations for the system’s usage. Summary of a practical example of new development.

The example is taken from a study that was conducted to examine the possible business opportunities of an aircraft system for surveillance purposes, which means that the first three stages of the described concept methodology were conducted.

The study looked at an airborne ocean surveillance system for the border area between the North Atlantic and the South Arctic Ocean. The scenario description encompasses an expansive area where surface traffic is to be monitored and classified. Moreover, missions must be conducted in harsh weather and low temperatures, which are common in the area. Normally, the requirement for presence is twelve days per month, with the option of extending this to a continual presence. In the event of suspected irregularities, the perpetrator is to be identified and monitored until actions can be taken.

Decisions on actions are taken by a mission command stationed at the aircraft system's home base.

Examples of desired functions to solve the task with an airborne system are as follows:

  • Long-term sustainability as regards vehicles and personnel.
  • Highly advanced surveillance.
  • Communication equipment required for mission command.
  • Systems for identification and registration.

This establishes requirements for sensor functions for surface traffic detection, optical camera systems for identification, storage space for information and communications that can reach mission command.

A number of combinations of tactical and technical system solutions for conducting the task were examined. Once the study was completed, a decision was made to continue the concept work with an unmanned aircraft system. Factors behind the decision included the sustainability requirement necessitating 24-hour flight sessions, the ability of a smaller aircraft system to reduce costs for both systems development and operation and the assessment of major safety risks for airborne personnel for the described task.

In order to provide the functions described above, a surface-monitoring radar was chosen, which from a high altitude can cover large areas, along with an electro-optic system for positive identification at lower altitudes. Satellite communication for larger quantities of data is unreliable at the concerned latitudes. Instead, an additional UAV in the aircraft system to act as a communication relay was chosen to transmit information to mission command.

The results of the study

As mentioned previously, risk reduction is one of the cornerstones of concept development. The results of the study point towards a number of immature areas that require development prior and/or parallel to continued concept and systems development. Example needs include the development of a number or rules, standards and technical systems. Rules for unmanned flight in international airspace are established through international agreements, and such rules need to be interpreted in standards for the development and operation of unmanned systems. Moreover, there is a need for technology that enables rules and standards to be followed.

As the described practical example shows, there are solutions to meet the requested need, but there are risks that must be dealt with before a robust system can be developed.

The author´s reflections