Model-Based Systems Engineering - Case Study Example

Name : xxxxxx Tutor : xxxxxxx Title : Саr Рurсhаsе Соmраrisоn bеtwееn BМW 5 Sеriеs аnd Аudi А sеriеs Institution : xxxxxxx @2015 1. Abstract The following portfolio focuses on a stepwise analysis of Audi A Series and BMW 5 Series sedan cars to gain an in-depth understanding which will shed light on selecting which car a customer should purchase. The analysis will employ system engineering methodologies with the aim of coming up with a valid inference on which series the client should acquire based on possession of a well-known good engine, strong power, rigid car body and smooth design, as well as comfortable capability. 2. Introduction Choosing the best model of car to purchase requires ingenious evaluation methods and expertise to come up with meaningful, prudent and informed decisions. Translating one’s personal requirements into valid engineering design features requires wide knowledge, rich information and experience in the problem domain. Systems engineering is a development process or management tool to assist and support decision-making, policy-making, planning, and associated resource allocation or action deployment. A system has a structure to entire system and is made up of various other components. The process is defined by a multi-step methodology. Magerholm (1997). 3. Problem scoping The problem is scoping forces engineering designers and developers to consider determining the problem before making decisions. For better understanding of the system and its operational features as far as user requirements are concerned, there is the need to decompose the system into sub-systems. A system boundary is important in the study of the same. Endogenous Exogenous Environmental Seats:-material, flexibility, quality Tires and wheels Weather. Dashboard:-display, multimedia, remote control system, alarm, notification panel Head-lamps and infrared beams User expertise Chassis and axles Outer body structure Competition Engine power and Transmission Shape, colour and general appearance. User preference and fashion The approach fulfils a couple of important roles. It ensures optimized utilization of resources at hand. It also ensures that important resources are included in the engineering process. Topper and Horner (2013). It is at this level that the problem is defined whereby the definition entails the importance of the problem, the people affected by the problem. 4. Requirement Engineering 4.1 Customer Requirements Requirements analysis gets applied in developing specifications define how the system must perform. Therefore, the designer must understand the requirements in a precise, unambiguous describe the specific solutions that the client expects the system to perform; that is, quantity, quality, coverage, time lines, and availability. Design constraints. Defense Acquisition University (Anon., 2001). The client has a taste for a German-built sedan that implies that the customer requires real engine, high power, rigid car body and smooth design, as well as its comfortable capability. It calls for the comparison of two German-built sedan series of cars: AUDI A SERIES and BMW 5 SERIES. 2.2 Pairwise Analysis. System quality gets based on how close, and satisfactorily the final product addresses customer requirements. Getting priorities of customer requirements is essential to resource allocation. A pairwise analysis aims at ranking the requirements on some scale of preference. Requirement Rank Good powerful engine 1 Strong power 2 Rigid car body 3 Smooth body design 4 Luxurious and Comfortable capability 5 2.3. Technical Performance Measures. The customer requirements realized above are translated to respective system design requirements, which simplifies the designers work. These are usually depicted in a Functional Specifications Document. Priority Customer Requirement Design requirements attribute Engineering features 1 Good powerful engine High horsepower and torque ratings. High number of cylinders. Higher than 250HP and over 200lbs.-ft More than 10 cylinders 2 Strong power Transmission type. Larger number of gears in transmission. Both automatic and manual. More than 5 transmission gears. 3 Rigid car body Very strong metal used in constructing body and chassis. Strong material for components. 4 Smooth body design Visually pleasing exterior design. Size and position of lights, mirrors and cameras if any. High level of elegance and exclusiveness of body, trim bars, wheels. 2.4 House of Quality Design requirements are ranked based on the priority of implementation as specified by the user. Then their relationships to the engineering characteristics and each other are deduced. The house of quality allows the relationships and dependencies of the individual components of the system to be established. It clearly depicts design requirements in terms of priority and rank. The qualities with the highest dependence relationship are analysed first and those with least are analysed last. Engineering Characteristics Design Requirements Relative importance Over 250HP Over 200lbs.-ft Both manual and automatic transmission More than 5 gears Light and high tensile strength High level of elegance of body, trim bars and wheels High horsepower 10 3 1 1 1 0 0 High torque ratings 9 1 3 1 1 0 0 Transmission type 8 1 1 3 1 0 0 Large number of gears 7 1 1 1 3 0 0 Very strong metal for chassis, axles and body 11 0 0 0 0 3 0 Visually impressive exterior design 6 0 0 0 0 0 3 Relationships Strong 3 Moderate 1 Weak 0 4. System function definition 4.1 Function Analysis Logic refers to the flow of control and induction of inferences based on features provided. Function refers to the general operation of the cars under study. . 4.2 Concept Generation Under this, the customer requirements are traced back from the functionalities of the features of the cars studied. The requirements should get considered well, and the operation of all the characteristics of the car gets traced to the requirements. It is an important aspect of system engineering quality. All ideas are classed and traced back to user requirements. For example, considering rigid car body and chassis requirement, the concepts of high density materials, high hardness materials and weather proof materials that have been implemented in the construction can be drawn. 4.2 Sub-System Integration. Decomposing the system into sub-systems is important in understanding inputs and outputs of the system as well as the relationships between each of the sub-systems. The following is a tabular representation of system boundary. Endogenous Exogenous Environmental Seats:-material, flexibility, quality Tires and wheels Weather. Dashboard:-display, multimedia, remote control system, alarm, notification panel Head-lamps and infrared beams User expertise Chassis and axles Outer body structure Competition Engine power and Transmission Shape, colour and general appearance. User preference and fashion Functional Block Diagram (FBD) of the sedan car is built step-wise based in the system boundary chart above. It shows the relationship between the subsystems. It also shows how the subsystems are related and fitted to each other. Driver Driver Observer Road user Other vehicles System boundary Road Logic and Function in Relation to Client and Engineering Requirements. Comparing the two series of cars based on logic and function is a process that requires unbiased exhaustive juxtapose of their respective key features. i. Safety An infrared with the capabilities of night vision is used in BMW 5 series to detect any objects on the way that are subject to causing accidents. They include human beings, animals or other projects that come on their way. Detection is by use of thermal imaging techniques by use of the cameras and an image of the same displayed on the user control panel. The Audi A Series does not integrate vision capabilities BMW series gets incorporated with lane monitoring mechanism that warns the driver whenever the vehicle diverts from the driving lane. The Audi A Series is yet to offer a lane departure warning system. Automated parking, Wide area 3D View, as well as a rear Camera. The various viewing capabilities in the vehicle enable environmental monitoring of the vehicle`s vicinity in all directions. Such view helps both on the road or when navigating through obstacles especially when parking in a connected parking lots. BMW 5 series has a GPS system that enhances its navigation effectively. It performs this by giving directions, enabling remote locking and unlocking of the vehicle by use of a receiver and transmitter connected to the GPS. A driver can unlock the doors if keys are locked in. Both series have safety airbags both at passenger as well as the secondary passenger seat. The safety belts also have pretensions that adjust themselves, according to the size of the travellers in the vehicle. The car also gets equipped with anti-lock brakes that work efficiently especially in instant braking situations. Skidding also gets managed by the availability of movement control. BMW5 Series, also, has Active Protection. Collision potential with other vehicles has gets reduced in BMW series by use of Approach actuation techniques. In such a case, when the vehicles detect an oncoming vehicle or object, it automatically activates the brakes hence preventing head-on collision. In other instances, the mechanism automatically brings the car to a halt minus any intervention from the driver hence reducing chances of damage.The Attentiveness Assistant in 5 Series also monitors the driver’s advising the driver to take a lapse in driving. Based on the above, 5 Series wins the verdict as far as safety is concerned. ii. Warranty BMW manufactures offer free preventive and repairs for the products for three years from the date of purchase. BMW offers 45000 miles more servicing time than Audi. However, Audi also offers free maintenance for Audi A Series (4/50,000 vs. 1/5000). The implication of the above is that 5 Series wins the verdict on warranty. iii. Reliability The BMW 5 series can start in all weather conditions by use of a 900-ampere battery. The battery can handle immense electric loads. The Audi A Series' 380-amp battery is not as powerful implying that based on reliability again 5 Series carries the day. iv. Engine performance In terms of engine performance, BMW 5 series is superior to the A 6 series. The more powerful engine power makes 5 Series faster. v. Fuel Consumption and economy range BMW 5 Series’ 528i Sedan has superior fuel mileage compared to Audi’s A6 3.2 Sedan FWD based on the EPA test cycle. With the aim to counter Audi A6, BMW unleashed BMW 520d- EfficientDynamics (ED) model. The model promises supermini-rivalling carbon (IV) oxide emissions of 119g/km, plus claimed 62.8mpg fuel economy. 520d SE targets to reduce operational costs for businesses and private buyers. Consequently, according to BMW, these eco-friendly improvements have not compromised the car’s sharp driving dynamics and comfort. However 2.0 TDI SE guises, Audi Series’ A6 is still one of the finest posh models available. However, it may not rival the BMW’s low CO2 figure, the Audi A6 comes at a lower price and better furnished and equipped than its BMW competitor. The trend is that models fighting to have an edge in the automobile market need competitive tax bills, and that means low fume emissions and friendly prices. Still there is more to executive car success than the reduction of costs. Any model contending for class ought to be desirable, comfortable and enjoyable to drive and well equipped – an avenue where the Audi A6 scores so highly. Vosper (2012). Impressively very low carbon (IV) oxide emissions imply that the BMW 5 Series costs company users more inferior to the tax than Audi A Series. Compounded to its better fuel economy and the 5 Series claims a distant victory in this encounter. Under its motivation to reduce fuel costs. vi. Transmission An 8-speed automatic, however, happens to be standard. The 8-speed Steptronic transmission in 5 Series makes gear-changing natural and driving more manageable and convenient, as it ensures faster. The selector lever can get employed in changing gears manually. This enhancement in convenience makes 5 Series more desirable yet again compared to Audi A Series. vii. Braking and Halting/Stopping The braking powers are shown in the table: This intelligent energy management system implies that the alternator needs not to run permanently, reducing strain on the generator. The outcome is reduced fuel consumption and increased performance – classic BMW Efficient Dynamics. The 5 Series Sedan takes lesser time to stop than the A6: viii. Tires and wheels The capability of driving on flat tires for considerably long distance reduces the chances of traffic mess up in sedans. ix. Suspension and handling An active adjustable suspension system incorporated in the 5 Series Sedan counteracts cornering forces directly; this limits body roll and while enhancing handling and the vehicle’s stability. Audi does not offer an active suspension on the Audi A Series implying that it suffers the risk of experiencing handling difficulty and instability compared to its counterpart. With the 5 Series Sedan, the driver is allowed to choose an added-supple ride as it gives better suspension . The choice of the extra- supple ride enables the operator to mitigate fatigue on tedious trips, or during a sports setting; the suspension system also allows maximum control on bumpy, slippery tricky roads. The Audi A's suspension does not offer adjustable shock absorbers; making 5 Series Sedan more desirable yet again. x. Chassis With 5 Series, one has a direct projection of the racing feeling at the steering as received at from the road. The rigid chassis guarantees safety and best possible comfort. Taut and comfortable, 5 Series are dynamic and safe. The even weight distributions. 5 Series gets made of an aluminium integral rear axle that not only separates the besides enhancing tight gripping of wheels on the road. This rigidity provides maximum passenger protection by absorbing forces of impact in the incident of a collision. A self-levelling suspension is built-in as standard in the BMW 5 Series Touring. The suspension cancels out height differences between rear and front axle. Sensors fitted on the rear wheels automatically measure the distance between the road surface and the automobile’s body. Based on the weight of the load and driving situation, air capacity within the springs is adjusted to ensure optimum spring clearance; ensuring safety, agility, flexibility and security even when the car gets heavily laden. With the new 5 Series’ Dynamic Damper Control, (DDC) comes a better chassis. The system undergoes a self-adjustment process depending on the information gathered. It also stabilises and dampers on the car that in turn adjust their settings fast and precisely thus ensuring a better steering. These features despite coming at a price make the BMW Series superior to the competing Audi A Series. xi. Passenger space Based on the convenience, comfort and safety, 5-Series is famous for its cramped back seat, contrary, individuals at the rear part of Audi A Series will have plenty of space to stretch out. Unlike the 5-Series, Audi A drivers have reported less of a learning based on technology. Considering safety, the Audi A Series commands top crash ratings, whereas the 5-Series remains behind in the frontal crash tests. xii. Cargo capacity Audi A Sedan's lift-over is 28.2 inches whereas the 5 Series Sedan's trunk lift-over height is 26.5 inches. For a 5 Series to carry heavy load, the divisible back seat can xiii. Ergonomics It is easier for the driver to enter and exit the 5 Series Sedan as it provides a standard secure entry system that allows raising of the steering wheel. The Audi A Series requires extra costs to incorporate the secure entry system. The 5 Series Sedan provides a good display that reduces the burden and risk of diverting their eyes from the highway. The driver of the Audi A Series car cannot use the remote to operate the windows as the functionality is not supported. While moving with high-beams on, 5 Series initiates light sensitive sensors. In contrast, Audi has incorporated white LED technology as daytime running lights (DRL) in their Audi A Series. The unique shape of the DRLs has emerged as a trademark of sorts. LEDs have spread throughout the entire Audi A Series range of cars; however, the Audi A Series Sedan does not dim lights automatically.The 5 Series Sedan's provides a cooling effect during hot weather to ensure that the air conditioned front seats do not sting, contrary, Audi A Series cars do not offer The driver has to do both the parking and speed controlling. 4. Life-cycle phases It quantitatively evaluates of ecological aspects: emission of greenhouse gases, energy consumption and acidification or ‘summer smog’. Hackenberg (2014). Scope of assessment: a. Development phase: materials and semi-finished products. b. Production phase: component parts and complete vehicles. c. Use phase: fuel/electricity (including production). d. Recycling phase: The procedural manner of material recovery The primary emphasis of Audi is the evaluation of greenhouse gases. The nature of materials chosen determines the level of carbon(IV) oxide emissions that occur during component manufacturing. Use of aluminium results in increased emission compared to that which occur in the production of steel. 4.1 Audi A Series Thanks to an ingenious choice of materials and improved lightweight construction measures, the new Audi model series is 45kg lighter than its predecessor. To mitigate the adverse effect of the same, Audi A implements form-hardened steel panels that are not only ultra-strong and but also at the same time light. Extruded aluminium profiles are used to create side sills and roof, which are incorporated into the structure using cast aluminium nodes. The new models in both car models have had significant improvements both in performance as well as functionality and comfort. 4.2 BMW 5 Series The 2014 5 Series is not left behind, drastically growing and improving its sales while the competitors fight 4.3 Construction and Production. Audi A4 wiring BMW 5 Series Wiring diagram 5. Testing, Verification and Communication 5. Testing and Verification Testing is an iterative process carried out throughout the systems engineering processes with the aim of reducing development errors, limitations and deficiencies. Testing may involve components, the whole system, or user acceptance. IIHS performed roof strength tests on the two brands of cars. III. Fuel: From the various EPA tests performed on the two models, it has been found out that BMW 5 series has a better fuel efficiency than the Audi series. IV. Chassis: Standard cruise test reveals that, at over 70MPH, BMW experience less noise as compared to the Audi series model (69 vs. 72 dB). V. Breaking and control: BMW series has the best braking power by use of the most effective traction mechanism. It can handle up to 0.86G`s while Audi sedan can handle up to 0.86Gs. 5.2 Design Communication Plays an indispensable role in the project as it is employed in modelling ideas and presenting designs to clients. Many approaches can be applied in the connection to get immediate feedback from the target audience. 5.2.1 Prototyping Using of 3D drawings and diagrams can be employed effectively in communicating ideas about the operation of the cars to the clients. It can also entail labelled pictures that succinctly explain the process mechanisms and features. 5.2.2 Video Animations A video simulation is the most efficient communication that can be employed to demonstrate the operation of the cars as it is easy to follow and has a long-lasting impression to the brain. Reviews and Evaluation. From the preceding study, BMW’s 5 Series Sedan by far wins the verdict of being the most opulent and most modern of the two Series of sedan cars. Conclusion. Based on the previous systems engineering steps, BMW 5 Series has majority powerful features to those provided by Audi A Series. As per the user requirements, 5 Series has the greater engine power, high, rigid aluminium body, smooth and covetable design that provides hi-tech user experience. Consequently, its contemporary technology design ensures the best and most comfortable interior environment for the driver and passengers. Provision of messaging apps, automatic controls, display, infrared object detectors, auto parking aids and multimedia players make this model unrivalled. References. 1. Topper, S. J. Horner, C. N. 2013. Model-Based Systems Engineering in Support of Complex Systems Development. John Hopkins University. 2. Schomp BMW, n.d. BMW-5 Series vs. Audi A6 [online] (Updated n.d) [Accessed 17 May 2015]. 3. BMW, n.d. The BMW 5 Series Touring. [online](Updated n.d) [Accessed 18 May 2015]. 4. Motor Trend Magazine, 2015. Used 2010 Audi A4 Performance Specifications .[online](Updated 2015). [Accessed 18 May 2015]. 5. Defence Acquisition University, 2001. Systems Engineering Fundamentals. Fort Belvoir, Virginia: Defence Acquisition University Press. 6. Kelly Blue Book, n.d. 2014 Audi A6 Review. [Online](Updated 2015)[ Accessed 20 May 2015]. 7. Akita, 2013. BMW Wiring Diagrams. [Online](Updated 2013)[Accessed 20 May 2015]. 8. Edigreg, 2009. Autocheck Wiring Diagrams. [online](Updated 2012)[Accessed 21 May 2015]. Read More

Requirement Rank Good powerful engine 1 Strong power 2 Rigid car body 3 Smooth body design 4 Luxurious and Comfortable capability 5 2.3. Technical Performance Measures. The customer requirements realized above are translated to respective system design requirements, which simplifies the designers work. These are usually depicted in a Functional Specifications Document. Priority Customer Requirement Design requirements attribute Engineering features 1 Good powerful engine High horsepower and torque ratings.

High number of cylinders. Higher than 250HP and over 200lbs.-ft More than 10 cylinders 2 Strong power Transmission type. Larger number of gears in transmission. Both automatic and manual. More than 5 transmission gears. 3 Rigid car body Very strong metal used in constructing body and chassis. Strong material for components. 4 Smooth body design Visually pleasing exterior design. Size and position of lights, mirrors and cameras if any. High level of elegance and exclusiveness of body, trim bars, wheels. 2.4 House of Quality Design requirements are ranked based on the priority of implementation as specified by the user.

Then their relationships to the engineering characteristics and each other are deduced. The house of quality allows the relationships and dependencies of the individual components of the system to be established. It clearly depicts design requirements in terms of priority and rank. The qualities with the highest dependence relationship are analysed first and those with least are analysed last. Engineering Characteristics Design Requirements Relative importance Over 250HP Over 200lbs.

-ft Both manual and automatic transmission More than 5 gears Light and high tensile strength High level of elegance of body, trim bars and wheels High horsepower 10 3 1 1 1 0 0 High torque ratings 9 1 3 1 1 0 0 Transmission type 8 1 1 3 1 0 0 Large number of gears 7 1 1 1 3 0 0 Very strong metal for chassis, axles and body 11 0 0 0 0 3 0 Visually impressive exterior design 6 0 0 0 0 0 3 Relationships Strong 3 Moderate 1 Weak 0 4. System function definition 4.1 Function Analysis Logic refers to the flow of control and induction of inferences based on features provided.

Function refers to the general operation of the cars under study. . 4.2 Concept Generation Under this, the customer requirements are traced back from the functionalities of the features of the cars studied. The requirements should get considered well, and the operation of all the characteristics of the car gets traced to the requirements. It is an important aspect of system engineering quality. All ideas are classed and traced back to user requirements. For example, considering rigid car body and chassis requirement, the concepts of high density materials, high hardness materials and weather proof materials that have been implemented in the construction can be drawn. 4.2 Sub-System Integration.

Decomposing the system into sub-systems is important in understanding inputs and outputs of the system as well as the relationships between each of the sub-systems. The following is a tabular representation of system boundary. Endogenous Exogenous Environmental Seats:-material, flexibility, quality Tires and wheels Weather. Dashboard:-display, multimedia, remote control system, alarm, notification panel Head-lamps and infrared beams User expertise Chassis and axles Outer body structure Competition Engine power and Transmission Shape, colour and general appearance.

User preference and fashion Functional Block Diagram (FBD) of the sedan car is built step-wise based in the system boundary chart above. It shows the relationship between the subsystems. It also shows how the subsystems are related and fitted to each other. Driver Driver Observer Road user Other vehicles System boundary Road Logic and Function in Relation to Client and Engineering Requirements. Comparing the two series of cars based on logic and function is a process that requires unbiased exhaustive juxtapose of their respective key features. i.

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