Dimensional Analysis Conceptual Modeling Framework (DACM) and Requirements Analysis

Transcription

1 Dimensional Analysis Conceptual Modeling Framework (DACM) and Requirements Analysis Professor Eric Coatanea, Tampere University of Technology Faisal Mokammel, Aalto University

2 Design Process Design Process (Pahl and Beitz, 2007) Planning and clarifying Conceptual design Embodiment design Detail design Generates 1. Requirements Lists 2. Principle solution (Concept) Part 1: Tools and Methods for Requirements Engineering. Part 2: Dimensional Analysis Conceptual Modeling Framework. 2

3 Part 1: Tools and Methods for Requirements Engineering 3

4 Introduction and scope of the research :- Requirements Engineering: Process and Practices Eliciting requirements Modelling and analysis requirements Communication requirements Agreeing requirements Evolving requirements Requirements are formally documented or modelled in this phase Support of tools and methods are needed in this phase (why needed? eplained in net slide) Other phase of this process will be much easier if requirements modelling and analysis are done properly 4

5 Introduction:- Challenges in requirement modelling and analysis Non static requirements are evolve during the system development Time constraints + Compleity of the system + Limited human cognitive ability Rapidly changing competitive market 5

6 Introduction:- Relationship between requirements (eisting approach) Graphical Path in SysML(Req. to Req. ) Copy Derive Satisfy Verify Refine Trace etc. 6

7 Introduction:- Drawback of SysML graphical links SysML graphical links between requirements need to be define manually by the user. Defining links between requirements is a slow process which require human effort. This approach mainly focus on the purpose of modelling rather than helping user to understand the semantic relationship or interaction between requirements. How we can automatically link requirements and which will be useful for the Requirements Engineer? 7

8 Introduction:- How to help requirements engineers in modelling and analysis phases? Hypothesis: To improve current requirement management: Right requirement should be in the right category. Requirements should not be contradictory with the eisting system or the already composed requirements. There should be a way to find out links between requirements based on semantic similarity. Tasks to do: 1. Automatically creation of links between similar requirements. 2. Automatically creation of links between contradictory requirements. 3. Automatically creation of group/cluster of requirements based on there similarity. 8

9 Method:- Creating links (Similarity + Contradiction) between requirements Quality of output result heavily depend on How the requirements are written using natural language? We should do quality analysis of requirements tets to make sure, if it is error or ambiguous free Task to do: 1. Automatic quality analysis of requirements documents/model 2. Automatically create links between similar requirements 3. Automatically create links between contradictory requirements 4. Automatically create group/cluster of requirements based on there similarity 9

10 Part 1: Method:- Flow chart of proposed methodology Key technologies used: 1. Vector similarity analysis 2. LSA 3. K-means clustering 10

11 Intermediate Result 1:- Similarity Between requirements: Requireme Description nt ID Req00, The air defence system shall be able to support joint operations with longrange capabilities. Req01, The air defence should prevent airspace violation. Req02, Construction work should not start before 2016 Req03, Construction work should start before Req04, The air base-2 shall be able to engage X number of adversary fighters at the same time. Req05, The air base-2 shall have air-lift capability. Req06, The air base-3 shall have long-range (X km) air-to-ground capability. Req07, The air base-3 shall have short-range (X km) air-to-ground capability. Req08, The air Base-3 shall provide airspace surveillance operation. Req09, Number of combat personnel should be increased incoastal area. Req10, Number of total personnel should be decreased within Req11, The five stations should be available for air Base- 2 Req12, Near artic region electrical equipment operation temperature should be at least minus ten degree celsius. Req13, 20 F/A-18 Hornet should be operated. Req14 25 F/A-18 Hornet should be on the system Req15, Three F-15 fighters should be on the system. Req16 Not more than two F-15 fighters should be on the system Req17, Empty weight of F-16 fighter should be less than8,570 kg Req18, Weight of F-16 fighter should be less than8,575 kg. Eample of output: Similarity between requirements (for Req. 00) sim A k, B = j=l e l. a k l B i j a k l B i j Req00 Req05 Req19 Helicopter pad should be located near flying operations 11

12 Intermediate Result 2:- Contradiction links between requirements Type Antonym Description Contradiction eists due to eistence of antonym words. Eample Catalyst, Deterrent. Eample: Number of personal should be decrease in the factory. Number of personal should be increase in the factory. Negation Contradiction eists due to negative words. Eample: have not, do not. Eample: Temperature of the room should not be more than 25 degree Celsius. Temperature of the room should be more than 25 degree Celsius. Requirement A and B are contradictory if there is no possible way in which A and B are both true simultaneously. Contradiction type Epected Detected Numeric Contradiction eists due to impose different numerical specification for some system. Eample: Weight of handset should be less than 113 grams. Weight of handset should be less than 200 grams Structure Considering physical structure of the system, contradictioneists with the Requirements. Eample: Internet submarine cable link should be built between Czech Republic and Finland. Eplanation: It is impossible because Czech Republic does not have any costal boarder with Finland Leical Contradiction due to leical or semantic discrepancy. Eample: All the components of the system should be manufacture locally. Battery and power supply should be imported from Germany. Factive, World Knowledge Contradiction eists due to fact of established or previous knowledge. Eample: Sand from Sahara desert should be used for constructing the building. Eplanation: This requirement refers to impossible fact because of sand of desert is not suitable for construction work. Number of combat personnel should be increased in the coastal area. Number of total personnel should be decreased within 2020 Antonym 2 2 Negation 2 2 Numeric 2 2 Factive / Knowledge based Not able to give satisfactory result. 12

13 Intermediate Result 3:- Grouping/ Clustering requirements based on their types A = U S V T J K = K k=1 i C k i m k 2 Plotting requirements based on their coordinates 13

14 Combined Result:- Graphical representation of relations between requirements Color of the node: Same category Red links edge: Contradiction links Green links edge: Similarity links 14

15 Contribution Automated requirements analysis and modeling which includes Automated Quality Analysis. Automatically detect nature of relationship between individual requirements. Semi automatically classification of requirements. Present requirement model in a understandable way. 15

16 Use of the results 1. Search links between requirements 2. Fast requirement management by tracking contradiction between requirement 2. Store in a SQL database to reuse these requirements graph in future projects 16

17 Part 2: Dimensional Analysis Conceptual Modeling Framework 17

18 Problem and Opportunity How to Specify, Validate, and Repurpose simulation models using proven and repeatable science, engineering, and other disciplinary premises.

19 THE DACM FRAMEWORK: WHAT IS IT?

20 Why is the DACM Important and relevant? The DACM Framework enables stakeholders to optimize the specification of Reusable Modeling Primitives (RMPs) and facilitate their acquisition.

21 THE 3 PILLARS OF DACM Dimensional Analysis (DA) Bond Graph/Causal Graph Design Structure Matri (DSM)

22 DIMENSIONAL ANALYSIS Decomposes all physical phenomena into fundamental dimensions (length (L), time (T), mass (M), temperature (K), moles of substance (N), electric current (J), and luminosity (I)) e.g., Derives dimensionless Pi groups (~ clusters of variables) from singular variables of problem space Translates equations of variables into more-compact equations of Pi numbers Generates reusable Pi numbers for problem spaces having similar dimensions Facilitates requirement specification of model fidelity Informs Intellectual Property and Data Rights Management 22

23 DIMENSIONLESS PRIMITIVES: COMPUTATION PRINCIPLE Computing the surface S of a circle S R Variables Dimensions [L: Length, T: Time, M: Mass] S [L 2 ] R [L] π = S. R β π = S. R 2 S = π. R 2

24 BOND GRAPH AND CAUSAL GRAPH A domain-independent graphical description of dynamic behavior of physical systems A powerful tool for modeling engineering systems, especially when different physical domains are involved A form of object-oriented physical system modeling

25 DESIGN STRUCTURE MATRIX Enables modeling, analysis, visualization, and management of comple systems Employed in Product Design/Development, auto and building industry, ship design (US Navy) Principal uses include product architecture, process development, organizational planning Facilitates identification and depiction of dependencies among system components DSMs can be combined into Multiple Domain Matrices (MDM) for analysis across domains

26 LEGACY VS ALTERNATIVE MODELS Mier VS. Propeller 26

27 What is the DACM specification framework? Mier eample: 1- The system variables should have the following dimensions. T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power Mass Length Time Dependence direction 2- To comply with the system architecture, the variables should be interconnected according the following DSM matri. T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power T w N h d Feff + F1 v Fdrag - Q Pressure H D nu y t En Power T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power 3- The system laws should be composed of the following variables and eponents. Power En Pressure Pressure F Q Q y Fdrag v v Feff /2-1/ w w d h Dependence direction 4- The system laws should be inter-connected using the following DSM s coefficients. w N h d Feff F 1 F1 v Fdrag Q Pressure En Power (k1,1) w N 0 0 (k3, 0 0 (k4, (k4', ((k4'', (k2, n2) n3) n4) n4') n4'') h (k5, n5) 0 (k6, n6) 0 0 (k7, n7) (k8, n8) (k9, n9) d (k10, n10) 0 0 (k11, n11) 0 0 (k12, n12) (k13, n13) (k14, n14) Feff (k15, (k16, n16) n15) F Eff F (k17, n17) 0 0 v (k18, n18) (k19, n19) (k20, n20) Fdrag (k21, (k22, n21) n22) F drag Q (k23, n23) 0 (k24, n24) 0 0 Pressure (k25, n25) (k26, n26) 0 0 En Power (k27, 1) 5- The following contact variables are interfacing the laws (and parts) of the system. Dependence direction w N h d Feff F1 v Fdrag Q Pressure En Power w w N N N N N N h h h h h h d d d d d d Feff h F1=Feff-Fdrag F1 µ v d, v,n, h h h, v, Q Fdrag F1=Feff-Fdrag h Q v, h, Q - Pressure Pressure - En Power Power 27

28 How to compare the models? 1- Do we have variables with same dimensions (i.e. units)? Mier T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power Mass Length Time VS. Propeller T w Va g N D c θ P0.7R Pressure ρw Mass Length Time

29 How to compare the models? 2- Are the selected variables belonging to the same type of Bond Graph organs? T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power Source (effort) e f Transformer e f e e e e f Flow Junction e e f e e e e e Transformer e f f e Inertia f e Transformer f e f e Resistor f e VS. Source (effort) e f T w Va g N D c θ P0.7R Pressure ρw Transformer e f f e Flow Junction f Transformer e e e e e e e Inertia e e Transformer e e e e e e e Resistor e e 29

30 How to compare the models? 3- Are the variables connections similar in both DACM causal DSMs? Mier Mier Dependence direction T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power T w N h d Feff + F1 v Fdrag - Q Pressure H D nu y t En Power VS. Propeller Propeller Dependence direction T w Va g N D c θ P0.7R Pressure ρw T w Va g N D c θ P0.7R Pressure ρw 30

31 How to compare the models? Result: The parts of the specification model that can be etracted from the mier to develop the propeller model are: T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power Mass Length Time Mier Dependence direction T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power T w N h d Feff + F1 v Fdrag - Q Pressure H D nu y t En Power 31

32 How to compare the models? Result: The parts of the specification model that can be etracted from the mier to develop the propeller model are: T w N h d Feff F1 v Fdrag Q Pressure H D nu y t En Power Power En Pressure Q Fdrag Pressure F1 Q y v v Feff w d h w /2-1/ Dependence direction w N h d Feff F1 F1 v Fdrag Q Pressure En Power w (k1,1) N (k2, n2) 0 0 (k3, n3) 0 0 (k4, n4) (k4', n4') ((k4'', n4'') h (k5, n5) 0 0 (k6, n6) 0 0 (k7, n7) (k8, n8) (k9, n9) d (k10, n10) (k11, n11) 0 0 (k12, n12) (k13, n13) (k14, n14) Feff (k15, n15) (k16, n16) FEff F (k17, n17) 0 0 v (k18, n18) (k19, n19) (k20, n20) Fdrag (k21, n21) (k22, n22) Fdrag Q (k23, n23) 0 (k24, n24) 0 0 Pressure (k25, n25) (k26, n26) 0 0 En Power (k27, 1) 32

33 How to compare the models? Result: The parts of the specification model that can be etracted from the mier to develop the propeller model are: Dependence direction w w N h d Feff F1 v Fdrag Q Pressure En Power w N N N N N N h h h h h h d d d d d d Feff F1=Feff-Fdrag h F1 µ v d, v,n, h h h, v, Q Fdrag F1=Feff-Fdrag h Q h, v, Q - Pressure Pressure - En Power Power 33

34 OTHER USAGE OF DACM How to find design conflicts in a torpedo architecture? 34

35 Another usage of a causal graph: Search for Design contradictions Ma Min Feff Mass (M) Min Ma Speed (V) Min Ma Drag Force (F) Density of fluid (ρ) Ma Min Cd Min A Min T 35

36 The specification model usage Ranking the impact of the different specifications: List of variables and dimensions Variables SI elementary units Problem objective Speed (V) L.T -1 Torpedo reference surface (related the shape and length of the torpedo (A), Drag coefficient (Cd) 1 Dynamic viscosity of the fluid (μ) or Volumic mass (ρ) of fluid Temperature of the fluid (t) L 2 ML -3 T Causal graph Problem variables Reference Temperature of the fluid (T0) Mass of the torpedo (M) T M Drag force (F) MLT -2 Efficient Force (Feff) MLT -2 Values of the variables Variables SI elementary units Low level Performance variable (F) MLT -2 To be evaluated (V) L.T (A), L 2 1,5 4 High level To be evaluated DACM Laws of the system F. = 1 2. V 2. ρ 1. A 1. Cd Repeating variables (Cd) 1 0,1 0,5 (ρ) ML -3 0,179 1,03 Ranking the importance of specifications 6- The priority of the specifications is the following 36

37 An innovative solution Ma Min Feff Mass (M) Min Ma Speed (V) Min Ma Drag Force (F) Density of fluid (ρ) Ma Min Cd Min A Min T Super cavitating (Shkval torpedo) 37

38 Summary of the Framework - The DACM Framework in tandem with RE3 demonstrate that Dimensional Analysis (DA) Theory, Causal Graphs (CGs) and Design Structure Matri (DSM) provide effective and efficient specification, validation, and repurposing of simulation models. The DACM Framework provides a finger print of model specifications for a problem space. The technical specificity afforded by the DACM Framework provides a solid basis for Technical Data Packages used to designate Intellectual Property ownership and Data Rights management. 38

39 Thank You 39