The Approach for Identifying Opportunities in Product Innovation Design through Requirement Conflict Analysis

Abstract

This study introduces a method to explore and broaden potential design avenues for a product by identifying opportunities for innovative design through requirement conflicts. The process involves clarifying user-expected demands using the Ideal Final Result approach and identifying potential conflicts by assessing product performance constraints and user expectations. Utilizing standardized representations of requirement conflicts, a knowledge retrieval technique based on expanding co-referential relationships is applied to analyze these conflicts. A judgment matrix is created to pinpoint clues for recognizing innovative design opportunities initially. Furthermore, the nine-windows method is utilized to expand and identify innovation opportunities along the time and system axis, leading to the identification of two types of innovation opportunities and their expanded outcomes. Ultimately, the method’s feasibility and practicality are validated by identifying innovative design opportunities within the context of the alpine tunnel construction system.

1. Introduction

Opportunities for product innovative design encompass the initial creative concepts and design pathways that have the potential to drive technological advancement and change [1,2]. Enterprises can allocate resources more effectively in the realm of innovation by focusing on identifying these opportunities [3]. Although innovative product design is known for being time-consuming [4] and having a low success rate [5], the process of opportunity identification, occurring in the early stages, incurs lower costs [6] yet plays a significant role in defining product quality and manufacturing expenses [7]. This, in turn, proves beneficial in reducing the need for repeated design iterations and mitigating the risks associated with the overall design process. Consequently, effectively pinpointing opportunities for innovative design is crucial for achieving success in product development and design [8]. While brainstorming and trial-and-error approaches are commonly utilized for opportunity identification, they tend to be subjective, situational, and lacking in systematic structure, making it challenging to promptly pinpoint and capitalize on superior design opportunities [9]. Therefore, a more systematic and universally applicable method must be developed to streamline the process of identifying opportunities for innovative design.

The primary task of the opportunity identification process is to derive principle solutions based on the Product Design Specification (PDS), which typically includes design inputs, design objectives, design constraints, and product performance criteria [10]. User demand information primarily serves as a critical design input during the opportunity identification process. Various studies have highlighted that user demands are pivotal in driving innovative product design, as they help designers clarify product functions [11,12,13]. To some extent, the functionalities of the final product can be determined by these user demands [14]. Consequently, user demands can be extracted and represented as product functions. For example, in the literature [15], users’ complaints and other demands were transformed into product function requirements and integrated with the Kano model to drive innovative product design. However, as products become more complex and user demands for new products evolve, innovative product design now incorporates not only functional requirements but also quality requirements. This shift entails transforming user demands from functional to performance requirements [16], making the fulfillment of performance requirements the ultimate goal of innovative product design. Nevertheless, whether it is functional or performance requirements, the initial expression of user demand is often vague and unstandardized, making it unsuitable for direct use in innovative product design. To address this issue, Reddivari S. et al. [17] proposed a framework for extracting and visualizing user demand information from verbal communication, which helps refine and utilize user demands. Fantoni G. et al. [18] introduced a technical text mining tool to extract user demand information from technical documents and translate it into design specifications, thereby identifying opportunities for innovative design. Ding X. et al. [19] and Kriglstein S. et al. [20] standardized user demands by constructing user demand ontologies, facilitating computer-aided analysis of user demands and more effectively identifying innovative design opportunities based on those demands.

Moreover, existing research has highlighted that product innovative design is constrained by several practical limitations [21]. Identifying innovation opportunities solely based on user demands does not guarantee feasibility. Therefore, to discover opportunities for innovative design that align with both user demands and realistic constraints, it is essential to consider the role of design constraints during the opportunity identification process. For instance, Xue et al. [22] validated an improved production plan by taking design constraints into account. Similarly, Koga et al. [23] developed a guiding algorithm based on inherent product constraints to reduce design time and mitigate risks in complex systems. Additionally, to distinguish between different design constraints in various design processes, existing research categorizes them into three types: input constraints, process constraints, and output constraints [24]. In the initial phase of product innovation, which focuses on achieving the final product performance, output constraints related to product performance are primarily considered. However, conflicts may arise between user performance requirements and product performance constraints. Specifically, design principles that meet user requirements might exceed the scope of applicable design constraints. Such conflicts are fundamental reasons for a product’s failure to meet user demands [25]. Therefore, studies have approached innovation opportunity identification from the perspective of conflict resolution, utilizing two main identification methods [26]. The first method relies on engineering technology development principles, particularly the Theory of Inventive Problem Solving (TRIZ). Sheu et al. [9], for instance, integrated conflict problem analysis, the ideal final result method, and the nine-windows method to systematically guide designers in analyzing current design problems from multiple angles. However, using TRIZ theory requires a substantial professional knowledge base. The second method employs artificial intelligence technologies, such as expert systems and natural language processing. These technologies are primarily used to collect and extract relevant design knowledge laws to facilitate knowledge reuse, though they lack theories on human creative thinking and decision-making mechanisms [26]. To leverage their respective advantages, some studies have combined these two approaches to identify innovation opportunities. For example, Tan et al. [27] used TRIZ theory, including conflict resolution principles, the technology-evolution principle, and computer-aided innovation systems (CAIs) based on knowledge, to create a generation framework for new ideas in the fuzzy front end. However, the design knowledge within CAIs remains complex. Additionally, Chou et al. [28] proposed a new product ideas ideation method based on semantics, combining TRIZ theory (such as conflict resolution principles, the Su-field model), concept mapping, and fuzzy linguistic evaluation techniques. Nonetheless, the linguistic technique was primarily employed in the evaluation stage of the final new ideas, and it did not promote their generation. In conclusion, the dual shortcomings in opportunity identification have been rarely analyzed simultaneously in existing research, indicating a gap worth addressing in future studies.

In summary, the current methods for identifying opportunities primarily stem from cognitive, market demand, or technical system perspectives, offering valuable insights for this research. This study contends that a comprehensive consideration of the aforementioned aspects is essential for a robust identification of innovation opportunities. To this end, the paper advocates a holistic approach that integrates these elements. By leveraging the semantic analysis technique of demand conflict, the paper seeks to deepen designers’ understanding of existing needs and conflicts, while broadening the scope of opportunity recognition via the nine-screen method within the technical system framework. Building upon these principles, this paper introduces a novel opportunity identification methodology for product innovation design rooted in demand conflict analysis.

2. The Identification of Opportunities for Innovative Design Based on Requirement Conflict

2.1. The Identification Method of Opportunities for Innovative Design

The product serves as a specific embodiment that fulfills user demands. However, due to various constraints, there often exists a discrepancy between the envisioned product form and its actual realization. This disconnect is termed as a product requirement conflict, representing the clash between the desired goal and the present state. This study proposes an opportunity identification method for innovative product design centered on requirement conflicts. This approach involves initially identifying the conflict between the current state and the desired state, extending this conflict through semantic analysis, and pinpointing innovative design opportunities by examining the expanded conflicts from two innovation perspectives: improvement innovation and migration innovation. These perspectives correspond to different types of innovation as discussed in the literature [29]. By analyzing these extended conflicts, the method directs the product innovative design process, depicted in Figure 1. In this methodology, the existing product system represents the current product state, while the user’s anticipated demand derived through the Ideal Final Result (IFR) method embodies the desired product state. The objective of innovative design lies in transitioning from the current state to the desired state based on identified design opportunities. Nonetheless, during this transformation, various conflicts arise, leading to significant disparities between the current product system and user expectations, hindering the creation of user-satisfactory design solutions. Thus, by scrutinizing variances between user-anticipated demands and product constraints (such as performance and attribute parameters), requirement conflicts can be extracted. These conflicts are subjected to semantic analysis and expansion, and the resulting insights are integrated into the TRIZ theory analysis process to unearth innovative product design concepts.

2.2. The Identification Process of Opportunities for Innovative Design

The product innovative design opportunity identification method outlined in this study comprises three key stages. The first stage is the requirement conflict determination phase. Here, requirement conflicts are identified through a comparison of user-expected demands with product performance constraints, leading to the explicit goal of the innovative design. The second stage involves semantic analysis and expansion of requirement conflicts. During this phase, the texts describing requirement conflicts are standardized and broadened to facilitate the exploration of opportunities across various domains. The third stage is the opportunity identification phase for innovative design. This stage encompasses initial identification based on improvement innovation and migration innovation, as well as expanded identification using the nine-windows method. By employing these approaches, opportunities for product innovative design can be unearthed from multiple perspectives and dimensions. The comprehensive process is illustrated in Figure 2.

2.2.1. The Determination of Requirement Conflict

User demands serve as the primary catalyst for driving product innovation and establishing the design trajectory. Product performance encompasses both function and quality, where quality signifies the extent to which functions are realized [16]. Building upon functional requirements, performance requirements are introduced to enhance the realization degree of functions. By aligning with user function requirements, the ultimate design objective of the product becomes clear, leading to the definition of the ideal functional outcome and meeting user expectations regarding product performance. However, existing product performance constraints within the system pose challenges in meeting necessary performance criteria, often dictated by natural laws, design principles, and formulas [30]. A lack of awareness regarding these product performance constraints can lead to user demands surpassing the boundaries of performance constraints, creating conflicting demands that obstruct the product design process [31,32]. Identifying and addressing requirement conflicts early on in the design process is crucial to deliver a product that maximizes user satisfaction. The process of determining these conflicts is illustrated in Figure 3.

User demand is usually the requirement for product function. The function goal is the final design goal of the product. The IFR method can be used to express the product function goal as an idealized result, and the user-expected demand can be obtained. The user-expected demand determined by the IFR method does not consider any constraints, but the actual design process is affected by various product performance constraints. Therefore, the realization of the final design goal is limited when the function goal is taken in the idealized process. And the requirement conflict is produced between the idealized result and product performance constraint. A 4-tuple representation model is adopted to represent the requirement conflict $C_{UD}$ in this study as follows:

$$C_{UD}=\left\{D{O}_{Final},D{C}_{IFR},LF,CR\right\}$$

(1)

where $D{O}_{Final}$ represents the final design goal, $D{C}_{IFR}$ represents the idealized result of the product function goal, LF represents product performance constraint, and CR represents the contradictory relationship between the idealized result and product performance constraint. Because of the hierarchy of product function, the conflict between the subfunction and the idealized result can be expressed similarly.

2.2.2. The Analysis and Expansion of the Semantic Feature Texts of Requirement Conflict

Requirement conflicts often contain a significant amount of redundant and irrelevant information due to the vagueness of user demands. To facilitate the extension of requirement conflicts to other domains, it is essential to standardize the texts representing these conflicts. In this research, the product function is articulated in a “verb-noun” form [33], where the function’s characteristics are primarily conveyed through the verb. The level of function realization is further described by the quality of product performance. The adverb, a modifier of the verb, can be extracted to represent the quality of product performance. Moreover, the noun typically denotes the object of operation for the function, with the attribute characteristics of this object often forming the primary components of performance constraints. Identifying the performance constraints involves clarifying the attribute characteristics and the degree of their parameter sizes. Therefore, extracting the noun that signifies the attribute characteristic along with its modifying adjective helps articulate the product’s performance constraints. Similarly, product performance parameters can also be expressed through a “noun + adjective” structure. Finally, standardizing the contradictory relationship within requirement conflicts is essential, leading to a clearer representation, as described below:

$$CR=\left\{v+n+adv,adj+n_c,n_p+ad{j}_e\right\}$$

(2)

where v + n represents product function, adv is the adverb of the degree of function realization, adj is an adjective that describes the existing performance constraint parameter of the product, $n_c$ is the parameter name of product performance constraint, $n_p$ is the parameter name of product performance, $ad{j}_e$ is an adjective describing the feature of performance parameter.

For example, the requirement is “The filter plate filters impurities efficiently through a small filter hole diameter and requires no reduction in fluid pressure.” The normalization process is carried out, where v is “filter”, n is “impurities”, adv is “efficiently”, adj is “small”, $n_c$ is “filter hole diameter”, $n_p$ is “fluid pressure”, adj is “low”. So the result of normalization is: $CR=\left\{filter+impurities+efficiently,small+filterholediameter,fluidpressure+low\right\}$.

Formula (2) utilizes the co-reference index-based knowledge retrieval method [33] to enrich the semantic feature texts. By expanding the “adv” and “v”, various approaches for realizing idealized outcomes and meeting product function requirements can be derived. This expansion facilitates a more comprehensive understanding and analysis of product performance constraints by exploring related semantic feature words. The noun in the representation of product functions is not considered for expansion because it serves as the extracted term for the objective entity’s name, lacking extensive logical reasoning and being less influenced by the designer’s constraints. Similarly, the description words ($n_p+ad{j}_e$) of performance parameters are excluded since these parameters and their characteristics, serving as linking factors between conflicting entities, evolve with shifting user demands. The correlation between the expanded semantic feature words and the original ones is denoted by I, where words with a high correlation offer greater guidance in product innovation design. Finally, multiple sets of expanded requirement conflicts are generated, as illustrated in Figure 4.

2.2.3. The Identification of Opportunities for Innovative Design

During the process of identifying opportunities for innovative design, potential design avenues are unearthed by evaluating, selecting, and resolving requirement conflicts. By combining these clues with existing technical knowledge, opportunities for innovative product design are pinpointed. To unearth clues for innovative product design, a judgment matrix is established to assess and select the expanded requirement conflicts. Building on the preceding analysis, a requirement conflict may manifest as the challenge of maintaining product performance when enhancing a specific parameter to meet user expectations, resembling a technical contradiction in TRIZ theory. Consequently, the contradiction matrix and technical parameters from TRIZ theory are amalgamated to determine the resolution principles for the chosen requirement conflicts. This analytical journey of identifying innovative design opportunities is depicted in Figure 5.

(1)

The construction of judgement matrix. In the judgement matrix, the expanded words of the semantic feature words of the function realization degree ($\widetilde{\mathrm{adv}}$) or the expanded words of the functional semantic feature verbs ($\tilde{\mathrm{v}}$) are taken as the first column elements, and the expanded words of the performance constraint description words ($\widetilde{\mathrm{adj}+{\mathrm{n}}_{\mathrm{c}}}$) are taken as the first row elements. The value of other matrix elements can be 0 or 1 by experts. For the judgment matrix where the expansion words $\widetilde{\mathrm{adv}}$ are located, the matrix element value is based on whether the expansion requirement conflict is similar to the original requirement conflict. If it is similar, the matrix element value x = 1, otherwise x = 0. For the judgment matrix where the expansion words $\tilde{\mathrm{v}}$ are located, the matrix element value is based on whether the expanded function of the function verb can overcome the corresponding expanded product performance constraints in the first row. If it can overcome, the matrix element value x = 1, otherwise x = 0. Finally, the comprehensive correlation degree w of the expanded words can be calculated by combining the correlation degree I and the matrix element value, the calculation equation is as follows.

$${{\displaystyle w}}_{\widetilde{\mathrm{adv}i}}={\displaystyle \sum _{j=1}^j{x}_{ij}\times {{\displaystyle I}}_{\widetilde{\mathrm{adv}i}}\times {{\displaystyle I}}_{\widetilde{\mathrm{adj}+{\mathrm{n}}_{\mathrm{c}}j}}}$$

(3)

$${{\displaystyle w}}_{\widetilde{\mathrm{v}i}}={\displaystyle \sum _{j=1}^j{x}_{ij}\times {{\displaystyle I}}_{\widetilde{\mathrm{v}i}}}\times {{\displaystyle I}}_{\widetilde{\mathrm{adj}+{\mathrm{n}}_{\mathrm{c}}j}}$$

(4)

where the higher the comprehensive correlation degree of the function realization degree expanded words ($\widetilde{\mathrm{adv}}$), the better the ways for implementation of the function goal idealized results can meet user-expected demand. The higher the comprehensive correlation degree of the function expanded verbs ($\tilde{\mathrm{v}}$), the better ways for implementation of function can overcome the product performance constraints. Therefore, the expanded words with high comprehensive correlation degree can be given priority as the opportunity clues for product innovative design.

(2)

The determination of design principles. The expanded words of the semantic feature words of the function realization degree ($\widetilde{\mathrm{adv}}$) selected above and the expanded words of the performance constraint description words ($\widetilde{\mathrm{adj}+{\mathrm{n}}_{\mathrm{c}}}$) are transformed into the corresponding parameters of 48 technical parameters (TPs), so as to obtain the contradiction matrix and confirm the inventive principles. In addition, by comparing and analyzing the design information contained in the function verb expanded words and the original function verbs, the beneficial functional principles of the expanded words are extracted. The determination of the functional principles is mainly based on the experience and knowledge of the designer, and it is not in the figure.

Lastly, leveraging the chosen innovative design opportunity cues like expanded semantic feature words and design principles, designers identify opportunities for enhanced innovative design and migration-based innovative design rooted in their technical expertise. Opportunities for improved innovative design encompass enhancement concepts that achieve equivalent functional realization through alternative implementation methods, aligning with shifts in semantic feature words related to functional realization. On the other hand, migration-based innovative design opportunities involve the concept of transplanting functional principles from another system into the current product system, entailing the substitution of function verbs within a standardized representation.

Additionally, the nine-windows method is introduced for extended analysis to overcome the limitations of designer thinking, utilizing resources from different times and systems to identify opportunities for innovative design. This method displays design resources and information along both the time and system axes, leveraging the interrelationships among its multiple windows [34]. The crucial aspect of applying this method for extended analysis is to identify the specific objects and resources within each window. The nine-windows model can be constructed as follows: Set B represents the system resource set for each system state, with numbers 0, 1, and 2 denoting the past, present, and future states, respectively. The subscript p refers to the super-system, while the subscript b refers to the subsystem. The final model is illustrated in Figure 6.

Along the system axis, emphasizing the subsystem involves concentrating on internal resources crucial for product performance, pinpointing opportunities for innovative design within the system itself. Conversely, directing attention to the super-system enables thinking to transcend the constraints of the existing system, unveiling resources external to the system and identifying innovative design opportunities from broader perspectives. Regarding the time axis, opportunities for innovative design emerge through comparing the states of system resources across different periods, facilitating the identification of these opportunities through a temporal lens.

2.2.4. Flow of the Method

The figure above illustrates the implementation process of the proposed method. Initially, gather and analyze the initial requirements of current users to derive the anticipated user requirements. Simultaneously, assess the existing product system to identify conflicts in product performance and establish demand conflicts by aligning the expected user requirements with product performance conflicts. Subsequently, standardize the expression of demand conflicts, elaborate on the initial semantic features of demand conflicts, and evaluate the semantic feature text’s correlation to generate various sets of extended demand conflicts. Lastly, develop a decision matrix based on the initial and extended requirement conflict semantic feature text and contradiction matrix to ascertain the necessity for resolving demand conflicts. These conflicts are addressed through the application of inventive principles. By leveraging the 9-windows method, innovation opportunities are uncovered and expanded by considering viewpoints from both temporal and systemic dimensions.

3. Case Study

Rock burst represents a violent mountain disturbance characterized by rock dislodgement, expulsion, tunnel distortion, and related phenomena. It frequently manifests during the excavation of high mountain tunnels, significantly impeding the tunnel construction process. Consequently, for illustrative purposes, the identification of innovative design opportunities aimed at mitigating rock burst within the alpine tunnel construction system is highlighted as a demonstration of the proposed method.

3.1. The Determination of Requirement Conflict in Tunnel Construction System

Alpine rocks exhibit high hardness and brittleness due to gravitational forces and long-term crustal activity. Presently, explosive blasting is primarily employed in alpine tunnel construction. However, the intense vibrations generated during blasting disrupt the internal stress distribution within the mountain. Moreover, the irregular free surfaces resulting from tunnel excavation lead to stress concentration, culminating in rock burst incidents.

To diminish the risk of rock burst, an analysis of the tunnel construction system’s construction method revealed the desired outcome of segregating tunnel rocks using low-amplitude vibrations. Yet, due to enhancements in vibration performance parameters, the separation force was nearly nullified, impeding the destruction of the hard rocks. Consequently, the primary product performance constraint hindering the realization of the final design objective was the high hardness of the rocks. Ultimately, the identified requirement conflict between user expectations and product performance constraints centered on the interplay between “small-amplitude vibration” and the “high hardness of rock”.

3.2. The Analysis of the Requirement Conflict in Tunnel Construction System

For the requirement conflict between user demand and product performance constraint, the adverb “slightly” that can represent “small-amplitude” vibration was determined as the semantic feature word of user-expected demand. The final standardization form of the requirement conflict contradictory relationship is as follows: {slightly separate rocks, high hardness, reduce separation force}. And the knowledge retrieval method based on co-reference index [33] was adopted to expand the semantic feature texts, so as to understand the product performance constraints more comprehensively and obtain different ways for implementation of the user-expected demand. The expansion result is shown in

Table 1. The expansion result examples of correlative semantic feature texts.

Original Semantic Feature Word	Slightly	High Hardness	Separate
Expanded words based on co-reference index (correlation degree)	slowly (0.78) stably (0.57)	high abrasion resistance (0.84) high intensity (0.68) high toughness (0.80)	cut (0.67) rub (0.75) scour (0.78) extrude (0.72) corrode (0.78)

.

3.3. The Identification of Opportunities for Innovative Design in Tunnel Construction System

In order to look for more valuable opportunity clues of product innovative design in the expansion results of requirement conflicts, the judgment matrix was constructed by using the expanded words of function realization degree ($\widetilde{\mathrm{adv}}$), function expanded verbs ($\tilde{\mathrm{v}}$) and the expanded words of product performance constraints ($\widetilde{\mathrm{adj}+{\mathrm{n}}_{\mathrm{c}}}$). And the expanded words with higher comprehensive correlation degree, the innovative principles, and functional principles were selected as opportunity clues by calculation and reasoning. The analysis process is shown in Figure 7.

As can be seen from Figure 7, for the opportunity clues analysis of improved innovative design, the comprehensive correlation degree of “slightly” and “slowly” is higher, which means that the conflicts between product performance constraints and the two ways for implementation of function realization degree are more correlated to the original requirement conflict. Therefore, in order to satisfy the degree of function realization as “small-amplitude”, the current function can be improved through these two ways for implementation (“slowly” and “slightly”) and the corresponding inventive principles. As a result, the opportunities for improved innovative design identified initially are as follows.

(1)

Through “slightly” to achieve “small-amplitude” effect, and combined with the corresponding inventive principle: No. 10 Prior action, the innovation opportunity can be inferred: the prior action force is applied to the rock to be excavated in order to reduce the vibration force required during blasting, such as applying an outward pulling force or injecting expansion agent into the rock.

(2)

Through “slowly” to achieve “small-amplitude” effect, and combined with the corresponding inventive principle: No. 8 Anti-weight, the innovation opportunity can be inferred: the local mass is used to assist the blasting to separate rock, such as utilizing the gravity of the upper rock to reduce the vibration force required during blasting through excavating the lower rock first and placing the upper rock in the air and then blasting.

(3)

Through both “slowly” and “slightly” to achieve “small-amplitude” effect, and combined with the corresponding inventive principle: No. 26 Copying, the innovation opportunity can be inferred: the small blasting effects are duplicated and accumulated to form a large effect, such as multiple shallow blasting.

For the opportunity clues analysis of migration-based innovative design, the comprehensive correlation degree of “corrode”, “rub”, and “cut” are higher, which means that the functional principles referred to by these function verbs can better overcome product performance constraints. Therefore, these functional principles can be transferred from other system to this system. As a result, the opportunities for migration-based innovative design identified initially are as follows.

(1)

Through the comparative analysis of the functional principles referred to “corrode” and “blast”, the principle of consuming or destroying rock from the microstructure can be transferred and utilized, such as using strong acid, strong alkali, and other corrosive substances to destroy rock microstructure.

(2)

Through the comparative analysis of the functional principles referred to “rub” and “blast”, the principle of destroying and separating rock by using the more maneuverable action position of force can be transferred and utilized, such as “rub” is used instead of “blast” to change the action position from the inside to the surface.

(3)

Through the comparative analysis of the functional principles referred to “cut” and “blast”, the principle of force generation that has a smaller range of action of force can be transferred and utilized, so as to reduce the action range of force and make the force more controllable. For example, the action range of the force generated in the “cut” is surface, and the “blast” is space; “cut” is used instead of “blast” to make the force more controllable and avoid rock burst.

Furthermore, to broaden design thinking and comprehensively identify opportunities for innovative design, the nine-windows method was applied to expand and analyze along the time and system axes. Given the practical engineering nature of this research, it is vital to choose smaller time intervals and system-level differentiations for each window. This approach facilitates the derivation of more precise and tailored solutions. Ultimately, the specific system components of each window are depicted in Figure 8. The red and yellow boxes show the data that need to pay attention to during the process.

As an illustration of opportunities for enhanced innovative design, the utilization of prior action force was exemplified to expand potential innovative design opportunities within other systems, detailed in

Table 2. The expanded opportunities of improved innovative design.

System Name	The Examples of Opportunities for Product Innovative Design
subsystem	Pre-set an elastic structure for the anchor to increase the anchoring force
super-system	Pre-excavate the rock above the tunnel in a small area to strengthen the mountain or release the prestress
past system	Pre-measure the stress in the mountain to simulate and predict the rock burst
subsystem of past system	Pre-install survey equipment to collect data for a long time, so as to grasp geological information more comprehensively
super-system of past system	Pre-optimize the route with new criteria
future system	Pre-formulate countermeasures by analyzing the rock burst situation in the surrounding area
subsystem of future system	Pre-fabricate concrete support reinforced module to support and strengthen rapidly
super-system of future system	Elevated road is erected in non-alpine plateau areas to increase the overall elevation of the route gradually, so that the tunnel is located in the upper half of the mountain as much as possible to reduce the force of the upper mountain on the tunnel

.

As a demonstration of opportunities in migration-based innovative design, the example of migrating and utilizing a more maneuverable action position of force was employed to expand potential innovative design opportunities in other systems, as outlined in

Table 3. The expanded opportunities of migration-based innovative design.

System Name	The Examples of Opportunities for Product Innovative Design
subsystem	Replaced by machine, using mechanical splitting action field instead of blasting explosion field
super-system	Use the method of excavating from the top of the mountain downwards for the partial section of the tunnel to reduce the stress of the tunnel
past system	Introduce survey technology from other fields to conduct detailed survey of the interior of the mountain
subsystem of past system	Look for new measurement signals to more comprehensively survey the areas that cannot be surveyed at present
super-system of past system	Replace the diversion tunnel with paving, and the construction position is changed into the mountain surface from inside
future system	Move the concrete frame into the supporting position after the external prefabrication
subsystem of future system	Choose materials or principles with faster shaping speed
super-system of future system	Elevated road is erected in non-alpine plateau areas to increase the overall elevation of the route gradually, so that the tunnel is located in the upper half of the mountain as much as possible to reduce the force of the upper mountain on the tunnel

.

In conclusion, the process of identifying opportunities for innovative product design and presenting key findings were summarized and are illustrated in Figure 9 and Figure 10.

4. Discussion and Conclusions

This paper introduces a new method for product innovation design opportunity identification based on demand conflicts, aiming to generate innovative opportunities and design concepts that cater to user needs. The approach involves: constructing a standardized representation of requirement conflict text to facilitate cross-domain identification of innovative design; utilizing a judgment matrix to analyze and identify initial opportunities for innovative design; applying the nine-windows method to enhance these opportunities; illustrating the method through an example of identifying opportunities in a tunnel construction system, showcasing improved innovative design possibilities and migration-based innovative design options. The feasibility and practicality of this method can be validated through its systematic application.

The main aim of this research is to effectively identify and expand on innovative opportunities, a goal that has been largely met. However, this approach does have its limitations, notably the need for domain-specific lexicons to better explore and develop various potential design directions for products in different fields. While the focus of this study lies in identifying innovative opportunities, assessing the creativity in the detailed design proposals stemming from these opportunities is equally vital, warranting further investigation in our future work. This method is poised to offer a more concise and effective strategy for opportunity identification, enhancing the depth and breadth of innovative opportunity recognition. It can assist companies in creating a range of products that cater to customer needs, targeting specific market segments.