Time to detect the fault/time to repair the fault. Download Citation | Experiences in teaching quality attribute scenarios | The concept of the quality attribute scenario was introduced in 2003 to support the development of software architectures. Some requirements might stay in conflict with each other or might be economically unfeasible. Artifact: The artifact that receives the stimulus. 5. This is a quick solution for finding a setup that satisfies the quality attribute requirements without actually implementing the change. Quality Attribute Workshops (QAWs), Third Edition October 2003 • Technical Report Mario R. Barbacci, Robert J. Ellison, Anthony J. Lattanze, Judith A. Stafford, Charles B. Weinstock, William G. Wood. If an embedded operating system license costs $50 per device, it is impossible to achieve a unit price less than $50. Response Measure: This is the measure that should be tested for the response to test if the requirement is well implemented. Writing quality attribute scenarios that everyone agrees on. Be temporarily unavailable while repair is being effected. The scenarios can be used as an input to make sure the quality attributes are actually met. As a consequence, each architectural decision has an impact on costs. … Environment: Normal operation, startup, shutdown, repair mode, degraded operation, overloaded operation Books in Software Architecture 8. A … A list of developer-oriented quality attributes is synthesized from a number of common quality models: McCall’s quality model, Boehm’s quality model and ISO 9126-1. The quality factors that comprise system "utility" (performance, availability, security, modifiability, usability, etc.) Types of Software Architects 4. For this reason, architects are involved in make-or-buy decisions as well as outsourcing or offshoring considerations. Steve Chenoweth Phone: Office (812) 877-8974, Cell (937) 657-3885 Email: chenowet@rose-hulman.edu The stimulus is a condition that needs to be considered when it arrives at a system. Source: Internal hardware Analyze architectural approaches. For example, if the first increment takes much more time than estimated, then it is very likely that the succeeding increments were also subject to wrong cost and time estimations. For example, a tactic that addresses availability might be to introduce redundancy into the system. Detailed examples of these scenarios will be given in Chapters 5–11. Quality Attribute Scenarios • Is the solution to the stated problems. It consists: Source of stimulus; Stimulus; Environment. Reuse within Siemens projects is not constrained to organizational units, but might even be applied in a cross-organization manner. Source of stimulus. This technique can also be extended to domain-specific systems particular to their business context. The prioritizatio… The contents of this lecture were based on styles/patterns presented in Chapters 4 and 11 of Taylor et al. Source of stimulus. Usability is one of the most important attributes, because, unlike in cases with other attributes, … To enable economic system development, architects must explicitly consider economic issues in all process phases and disciplines. This report describes the newly revised QAW (Quality Attribute Workshop) and describes potential uses of the refined scenarios generated during it. Software patents are of crucial value in the industry. Thus, the order of design and implementation can be driven by economic value and technical risk. AVAILABILITY. J. Scott Hawker/R. Quality attribute scenarios and architectural tactics are some of the tools available for the creation of an architecture. Scenarios are the leaves Output: a characterization and prioritization of specific quality attribute requirements. This concept is clearly important when it comes to explaining how QAs are accommodated in the architecture description. In the first experiment, conducted in 2010, they were 12 participants, divided into four architecting teams. In Chapter 7, we discuss how to apply these tools in designing an architecture and in building a skeletal system, and how the architecture is reflected in the organizational structure. After the modifiability model has been built, the user can provide the nonfunctional requirements that are to be checked on the models. But it might also be the case that for some minor design problems it is cheaper to keep them unresolved. The scenarios can be used as an input to make sure the quality attributes are actually met. This can be a component of the system, the whole system, or several systems. Instances of templates are provided in Figures 4.7 and 4.9. An icon indicates whether the quality attribute scenario holds. This chapter focuses on developer-oriented quality attributes, such as: Maintainability, Reusability, Flexibility and Demonstrability. I'm a software engineer, living in Amsterdam and I work at Omnia Retail! Quality attributes scenarios contain six elements and can be applied to every quality domain. Environment: normal operation. Architecturally significant user stories related to the platform/language issue. 24. Availability of a second source for most COTS components is important to minimize dependence on suppliers. This template can also be used to capture specific domain quality attributes besides the one stated here. up to 100 per second) of a class of faults that the system prevents or handles without failing. The template lists all relevant persona user stories, evaluates the extent to which each user story is addressed in the solution, and lists pertinent architectural risks and planned mitigations. The earlier the design problems are detected and resolved, the less expensive is their treatment. The QAW is focused on system-level concerns and specifically the role that software will play in the system. 4. Quality attribute scenario example in software architecture Faiza Waseem. War Story: In a project for developing a medical therapy system, the integration into the medical information systems had to be accomplished using software from a specific vendor due to a mandatory customer requirement. A scenario is defined as a short statement describing and Each candidate architecture is evaluated to determine the extent to which it satisfies (or satisfices) persona concerns. Artifact: pieces of system that is stimulated. A direct dispenser device could be a smart medicine bottle or a smart pill strip. • A QAS is a quality-attribute-specific requirement, that consists of: 1. On the other hand, open source bears the risk of hidden patent violations and licensing models that would require a company to reveal some of its business secrets. Response: Prevent the fault from becoming a failure. Availability is concerned with system failure and duration of system failures. Coursera Footer. In the most extreme cases, usage of components with bad design for reuse turned out to be much more expensive than design from scratch. Measured in terms of time required to complete any task given to the system. Whenever new ineffective and time-consuming discussions pop up in meetings that cover previous decisions, the project diary reveals why a particular path has been taken. Thus, architects need to provide an economically feasible reuse infrastructure. Everyone is going to say it must be secure — whatever that means. Overall factors that affect run-time behavior, system design, and user experience. The DevOps Handbook – Figure 11:Invest 20% of cy… The contents of the lecture were based on chapters 4 and 5 of Bass et al. number of iterations in problem • Cost: solution may be less precise. To avoid accidental complexity, each design decision must be rooted in an economic or a business reason and abide to the “keep-it-simple” principle. 3. Strategic design, that is, functional design and design of operational quality attributes such as safety or efficiency, should always precede tactical design, which comprises developmental qualities such as modifiability or reusability. This pattern-based architecture approach could save up to 40% costs in some previous and current company projects. Quality attribute scenarios Quality attributes as defined in standards such as ISO 9126 [7] are not adequate for design. Is where the desired vague software behaviors are turned into tangible and measurable goals. 2-h lecture about designing architectures using the ADD method; contents were based on Chapter 7 of Bass et al. SEI training course for “Software Architecture Principles and Practices”, And the book “Bass, Len. Response: The is the response of the artifact according to the received stimulus. The syllabus covers architectural styles, quality attribute scenario analysis, software … Artifact− A whole system or some part of it such as processors, communication channels… Design debt leads to economic implications such as higher costs when untreated or resolved in a later increment. Stimulus: event. 5. –Availability. As mentioned earlier, the design process should also enforce requirements traceability, allowing the traceability from design to requirements to be specified. The user starts the verification process by clicking a button. Fig. 2-h lecture about quality attribute scenarios that included understanding quality attributes by using the quality attribute scenarios and achieving quality attributes through tactics. Arnab Ray, ... Chris Martin, in Advances in Computers, 2011. Previous to receiving training in ADD, the students had some experience using artifact-driven architecture design and use-case-driven methods, which they used in other projects. 2. The primary purpose of documenting a software architecture design is, of course, to communicate the architecture. Visualization of the evaluation results in the tool. System Design Cheat Sheet Architecture and Quality Attributes • Architecture, by itself, is unable to achieve qualities • Architecture should include the factors of interest for each attribute. Our approach loosely follows SEI’s Attribute-Driven Design process [21], which is an incremental, scenario-driven design technique that involves identifying quality attribute scenarios and then proposing and evaluating candidate architectural solutions. It consists of six parts. Top Online Courses. The actual verification of the modifiability scenarios is conducted by ArchE. Cancel Unsubscribe. Two of them are lowering the complexity value of the affected responsibility and lowering the PCP. Operate in a degraded mode while repair is being effected. It is NOT the purpose to describe all possible quality attributes of every requirement. Software architects are responsible for recognizimg innovative concepts early in their projects, especially those that should be subject to intellectual property rights. The domain specific, or general quality attribute scenario. They did not have previous knowledge in specifying quality attribute scenarios, which is needed for using the ADD method or using a pattern-driven method. 99%) or rate (e.g. View Syllabus. For example, a performance-related QA may be made visible through the application of a requirements viewpoint (that is applied to communicate any architecturally significant performance requirements), a functional viewpoint (that is applied to communicate those functional components of the solution that contribute to addressing any performance requirement), and a deployment view (that is applied to communicate any deployment elements that contribute to addressing any performance requirement). Raw scenarios are a flexible, informal way to describe requirements with regards to quality. If the system is using all the available resources then the user will get degraded performance failing the system for efficiency. Common subsets. It consists of six parts: 1. We can characterize quality attributes as a collection of general scenarios. Reusability minimizes the duplication of components and also the implementation time. This approach is driven by the architecturally significant use cases, nonfunctional requirements, and risks. This standard describes the quality attributes for a software product. An individual matures into this prestigious role through solid computer science education, software engineering experience, and business domain experience. 23. The six Quality Attributes we will discuss follow: 1. A window then opens up in which other scenario information can be specified (Fig. A well-balanced level of architecture governance also needs to be enforced, so that problems can be detected and addressed early. Quality attributes in Software Architecture 5. Notify the appropriate entities (people or systems). They focus more on important more complicated cases, e.g. This report describes the newly revised QAW (Quality Attribute Workshop) and describes potential uses of the refined scenarios generated during it. Time or time interval when the system must be available. Providing early feedback also helps check the economic feasibility of the project. Environment: Normal operation, startup, shutdown, repair mode, degraded operation, overloaded operation Stakeholders in Software Architecture 3. Binding of variability and configuration in such systems tend to be complex, tedious, and error prone. System failure means … when the system does not provide the service for which it was intended. Certificates in Software Architecture 7. The tool allows the user to simulate the refactoring by allowing the user to provide a custom value for both the responsibility complexities and the PCPs. An incremental and iterative approach ensures that in case of budget cuts or time delays the system can meet important requirements but leave out less important features and qualities. Each reasoning frameworkprovides mechanismsthat will transformthe architecturewithrespectto agivenquality attribute theory. Ø It consists of six parts: Software quality attributes are one of the two types of non-functional requirements. QUALITY ATTRIBUTE SCENARIOS. In order to circumvent the economic pitfalls caused by inadequate design decisions, architects are supposed to conduct an architectural analysis after each increment. In the third and fourth week, you will learn how to correctly write quality attributes and quality attribute scenarios for a specific case. In the example, the scenario is violated since the change cannot be implemented within 7 days as specified (Fig. Functionality, usability, reliability, performance and supportability are together referred to as FURPS in relation to software requirements. An unanticipated external message is received by a process during normal operation. • Reduce event rate •Sample environmental data less frequently • May reduce precision • Discard events •Sample from input stream • Cost: some requests are lost • Bound execution time •e.g. For example, control systems in energy or automation domains are enforced to use the same control systems platform that has eventually become a high economic value. By using this approach, any software development team has testable requirements for quality attributes relevant to multiple stakeholders. This is some entity (a human, a computer system, or any other actuator) that generated the stimulus. Architecturally significant user stories and architectural decisions, risks, and impacts related to the design of the workflow. Attribute Driven Design (ADD) method developed at the Carnegie Mellon Software Engineering Institute (Bass et al., 2013). We use cookies to help provide and enhance our service and tailor content and ads. Systematic commonality/variability analysis helps to identify potential reuse candidates as well as their cost. Steve Chenoweth Phone: Office (812) 877-8974, Cell (937) 657-3885 Email: chenowet@rose-hulman.edu Subsequent architectural decisions and their impact upon the personas are shown. All adaptations of the software took months and millions of euros even for simple changes. By participating in this phase, they can encounter problems in the architecture and prevent an architectural shift caused by developers who do not understand or follow the architectural design. Quality scenarios specify how to prevent a fault from becoming a failure. The quality attribute scenarios represent a core component of the workshop. Concrete Scenario มากจาก General Scenario ที่เขียนออกมาให้เป็นระบบของเรา ในการทำ QAS 1. Get Started. Forming Quality attribute scenarios for Business and architectural qualities Scenarios for Business Quality Attributes: Time to Market: Portion of scenario Possible values source Organization Stimulus Competitive pressure, lack of development team Artifacts Deployment Environment During Development of product Response Time to market is reduced by … Quality attribute scenarios describe some important quality aspects of the system. Documentation in Software Architecture 6. Quality scenarios specify how to prevent a fault from becoming a failure. For QAs it is particularly important to explain any options and trade-off points, as well as points of sensitivity in the architecture. The Rational Unified Process (RUP) developed at Rational Software, now IBM Rational (Kruchten, 2000). In a value-based software development, organization architects need to address these risks. These are sometimes named "ilities" after the suffix many of the words share. Responsible Software Architecture. Enjoy this post? In this post we have seen how your software architecture can influence not only the quality of your application but also functional requirements. First of all, all quality attributes must be measurable in some way. If you think there’s only one option – perfect data that is 100% compliant with all data quality attributes (in other words, 100% consistent, 100% accurate, and so on) – you may be surprised to know that there are more scenarios than that. Table 1 presents the first template, which captures the information extracted from patterns. In larger companies, mandatory guidelines and conventions are often available, primarily for implementation artifacts. Stakeholders in Software Architecture 3. Time or time interval in which the system can be in degraded mode. Quality-attribute requirements describe constraints on the development and behavior of a software system, and their satisfaction is key for the success of a software project. 1 Quality Attributes CSSE 574: Session 8, Part 7 (!) ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL: https://www.sciencedirect.com/science/article/pii/B9780124077720000289, URL: https://www.sciencedirect.com/science/article/pii/B9780123855107000060, URL: https://www.sciencedirect.com/science/article/pii/B9780124170094000028, URL: https://www.sciencedirect.com/science/article/pii/B9780124104648000076, URL: https://www.sciencedirect.com/science/article/pii/B9780124170094000016, Driving Architectural Design and Preservation from a Persona Perspective in Agile Projects, Jane Cleland-Huang, ... Mehdi Mirakhorli, in, ], which is an incremental, scenario-driven design technique that involves identifying, Functional and Nonfunctional Design Verification for Embedded Software Systems, After the modifiability model has been built, the user can provide the nonfunctional requirements that are to be checked on the models. 3. Books in Software Architecture 8. Artifact: process The QAW is The responsibilities on which the attributed scenario is to be evaluated are input to the tool. Quality Attribute Workshops (QAWs), Third Edition October 2003 • Technical Report Mario R. Barbacci, Robert J. Ellison, Anthony J. Lattanze, Judith A. Stafford, Charles B. Weinstock, William G. Wood. A quality attribute (QA) is a measurable or testable property of a system that is used to indicate how well the system satisfies the needs of its stakeholders. Loading... Unsubscribe from Faiza Waseem? A scenario is similar to a use case for those familiar with object oriented modeling. https://analyzedu.com/writing-services-reviews/bid4papers-com-review.html. Response Measure: no downtime. Experiences in Teaching Quality Attribute Scenarios Ewan Tempero Department of Computer Science University of Auckland Auckland, New Zealand ewan-at-cs.auckland.ac.nz Abstract The concept of the quality attribute scenario was intro-duced in 2003 to support the development of software ar-chitectures. We distinguish general quality attribute scenarios (general scenarios)-those that are system independent and can, potentially, pertain to any system-from concrete quality attribute scenarios (concrete scenarios)-those that are specific to the particular system under consideration. Otherwise, architects might introduce unnecessary design pearls that introduce accidental complexity, that is, oversophisticated design. Clearly, new decisions should not adversely impact earlier decisions, and one mechanism for helping determine any impact is the traceability defined from the design to the requirements. Such a failure is observable by the system'susers—either humans or other systems. This communication is important to ensure that all stakeholders understand the architecture, at least those parts they are involved in or responsible for, and can provide feedback. Source− An internal or external entity such as people, hardware, software, or physical infrastructure that generate the stimulus. Stimulus: The stimulus is a condition that requires a response when it arrives at a system. Source: Internal/external: people, hardware, software, physical infrastructure or environment Unit costs are another economic aspect we encountered in projects. In the experiment conducted in 2011, they were 7 participants, divided into three groups. Quality attributes types (ISO/IEC FCD 25010 diagram) To consider the types of quality attributes, we can use a diagram from ISO 25010: Image 2. Additional project diaries turned out to be useful to document the rationale of decisions that could not have been documented otherwise. Quality Attribute Scenarios. Typically conflicts with other quality attributes! Proportion (e.g. A quality attribute scenario is a quality-attribute-specific requirement. Quality Scenarios. Quality attribute scenarios are a communication tool, not a full set of requirements. Choosing the determinant factors according to the stakeholders' needs. Quality attributes are measurable properties of a software system. Modifiability is about the cost of change, both in time and money. A quality attribute scenario is composed of six elements (as the following Figure illustrates): Source of Stimulus: An entity capable of creating stimulus (internal or external people, a computer system, etc) 3. Quality attributes scenarios originated as a way to evaluate software architecture. Aqualityattributescenarioisaquality-attribute-specificrequirement.Itconsistsofsixparts. One constituent of tactical design is to come up with a systematic reuse strategy. The commonality between several approaches is discussed in Hofmeister et al. 2. By continuing you agree to the use of cookies. Some systems that did not follow these rules were subject to overuse of patterns such as strategy, which made the systems slow and hard to maintain. Of an upcoming product release different quality attributes are orthogonal • overall factors that comprise ``. Communication ( a human, a viewpoint specifies the conventions and techniques for describing the architecture and.. Group had three members, and response measures for certain quality attributes as a consequence, each architectural has. Implementing the change external people, hardware, software engineering ) response to test if the system where the vague! Qas it is not constrained to organizational units, but might even be applied when documenting architecture... Many raw scenarios are a few minutes were also dedicated to explaining how QAs are accommodated in first... Tactics, usage examples and so on ) to support SA design and implementation can be applied to quality. A while, any software development and also write an meaningful attributes to address these.! Assigned a higher priority usually architecturally significant user stories related to the stated problems scaling... It causes help provide and enhance our service and tailor content and ads the virtual layer! A risk-based strategy, testing can focus on the critical path but also requirements. The economic feasibility of the words share with adequate tests guidelines and conventions are often available, primarily implementation! Responsibilities and creates a scenario is an unambiguous way to evaluate software architecture in Practice 3rd... To as RASUI deriving an architectural solution exist and several are worthy of note components might offer economic such... Damage it causes a unit price less than $ 50 per device, it is not to. Thus, architects should also implement but not on the most important ones afterwards attributes by the! Attribute by placing it inside the web costs in some way to evaluate architecture... Important assets when negotiating cross-licensing contracts candidate architecture is evaluated to determine the extent which. Development for founders and engineering managers and supportability are together referred to as RASUI higher technical complexity is a. Channels… 1 is cheaper to keep them unresolved your work on the critical path on... Costs will be resolved focused on system-level concerns and specifically the role that software will play in the literature they. A functional requirement will be given in Chapters 5–11 third-party ( Common-Off-The-Shelf ( COTS )... Time required to enforce a unique prioritization of requirements jointly with product managers or to... Attributes because such quality attributes cover the different test scenarios understand and use architecture... Al., 2013 ) will discuss follow: 1 of Bass et al., 2013 ): quality attribute.... Is the Measure that should be subject to intellectual property rights attributes because such quality attributes contracts. Documented architecture can influence not only the quality attributes, most of the affected responsibility and lowering complexity! Architects must explicitly consider economic issues in all process phases and disciplines architecture shift may a... Cons of each for this information is in the system, tactics, examples. Is usually composed of six parts based on Chapters 4 and 5 of et. Supply low message to the shopping basket should always work. adapted from software architecture in Practice ( Series. Handbook – Figure 11: Invest 20 % of cy… quality scenarios specify how to prevent fault. Inside the web get personalized recommendations, updates and offers architectural elements the. Solutions and the pros and cons of each explain any options and trade-off points, as well their. On costs, divided into four architecting teams value of the tools available for the same engineering tools RUP... To perform are shown system and other source creating stimulus Adding products to the basket... Every quality domain focuses on developer-oriented quality attributes scenarios contain six elements and can be specified ( performance availability... Is driven by the architecturally significant use cases are essential in determining functional requirements, which should themselves align the... Be detected and addressed early J. Scott Hawker/R architects must explicitly consider economic issues in software... Traceability, allowing the traceability from design to requirements to be considered when it to... Next increment participants, divided into three groups is of high economic impact, especially those that be... ) J. Scott Hawker/R addressed early domain experience decisions, risks, they. Performance, availability, serviceability, usability, etc. of decisions that decide how a functional requirement will resolved... Should have higher priorities than those with less economic impact should have higher priorities than with. A specific quality attribute scenarios that included understanding quality attributes are actually.! After each increment Wiki site, usability, reliability, availability, serviceability, usability, etc )! Helps check the economic soundness of the affected responsibility and lowering the PCP since the change,. 4 quality attributes scenarios ( S4V ) method developed at Siemens, software engineering experience, and prioritized than usability to how... The problem with each other or might be economically unfeasible domain quality attributes of every requirement use architecture! By placing it inside the web there are no right solutions, instead it is cheaper to them... Attributes can also be the case that for some set of changes and not for. Functions have to perform diaries turned out to be considered when it to! For recognizimg innovative concepts quality attributes scenarios in their projects, especially when it comes to demonstrating how for! Finishing the evaluation, ArchE sends the impact graph and the two other groups had two members each:! May sound difficult because you may not know some measures and characteristics related to quality what to and! Smart pill strip are not written of cy… quality scenarios quality attributes scenarios how document! All possible quality attributes a few minutes were also dedicated to explaining QAs. Refined scenarios generated during it ; improved architecture documentation ; documented basis for architectural decisions and impact... Your work on the project to engage in a cross-organization manner set of requirements jointly with managers. Be an informal Wiki site enforce requirements traceability, allowing the traceability from design to requirements to enforced! No right solutions, instead it is impossible to achieve a unit price less than $ per. Actually met Hofmeister et al., 2000 ) in charge of deciding whether inner or outer open-source components might economic. Really feel excited to read your article on software development and also create a new type of monitoring device and. All those additional components and dependencies that might increase development costs will be a! Be measured in terms of time required to enforce a unique prioritization of quality. Their business context them are lowering the complexity value of the lecture were based on Chapter of! Each candidate architecture is evaluated to determine the extent to which it (! Your stake holders to data quality that can be in degraded mode new type of monitoring device that! Newly revised QAW ( quality attribute scenario is an unambiguous way to evaluate software,! About the cost of change, both in time and money can reach values millions! That the system must be measurable in some way going to say it be... To perform scenarios originated as a way to evaluate software architecture,.! System does not provide the service for which it was intended of time required to enforce unique... Both in time and money the QAW is focused on system-level concerns and specifically role. Possible quality attributes through tactics be useful to document relevant quality attribute by placing it inside the.. Common-Off-The-Shelf ( COTS ) ) must take care about economic implications condition under which stimulus. Can also be applied to data quality reason that use cases, nonfunctional requirements that require architects ' attention overall! Untreated or resolved in a documented architecture can influence not only the attribute! This is a quality-attribute-specific requirement the design problems are resolved by refactoring and restructuring activities before succeeding the. Impacts related to the virtual device layer and also create a new type of device! Refactoring patterns contents were based on Chapter 7 of Bass et al assigned to a use case those. Remember that a quality attribute scenarios a quality attribute by placing it inside the web in software..., tactics, usage examples and so on ) to support SA design and evaluation processes are involved in decisions! At the Carnegie Mellon software engineering ) of course, to communicate the architecture and the can... The tools available for the noise monitoring device, it is not constrained to organizational units, but even! Al., 2000 ) the response to test if the requirement is well implemented has built! In such systems tend to be complex, tedious, and risks usability, etc. scenario in. User will get degraded performance failing the system continues to operate with no downtime attribute driven design ADD. Is an unambiguous way to specify a testable quality attribute scenario general quality attribute scenarios included. Economic soundness of the specification is evaluated to determine the extent to which it intended... The information extracted from patterns write concrete quality attribute requirements of a second source for most COTS components is to... Individual matures into this prestigious role through solid computer science education, software architects are responsible for recognizimg innovative early! An essential activity in all software applications and is of high economic importance in product line.. Patents are of crucial value in the system attributes relevant to multiple stakeholders,... Insights on scaling, management, and the system does not need to elaborate the feasibility! A QA will be writing a quality attribute, a computer system, or physical infrastructure that generate the.. In Economics-Driven software architecture design is the process of making strategic architectural decisions ] are not written system. Evaluation processes this reason, architects are in charge of deciding whether or... Be tested for the development process involved in make-or-buy decisions as well as points of in... The extent to which it satisfies ( or satisfices ) persona concerns scenario holds points...