Five Step Approach To Architectural Modeling

Published Date: 02 Nov 2017

Chapter 1

Introduction

Standardization for manufacturing in general is an idea that was sparked by the need for common interchangeable parts. Early mass production was nothing more than individual craftsmen creating and fabricating parts which led to difficulties when parts failed as the damaged or broken part had to have custom work done to it. This was seen as highly inefficient, and to remedy the situation for industries assembling items with interchangeable parts a revolutionary solution arrived in the form of the assembly line.

The wide range of companies and organizations are involved in designing, development, manufacture, marketing, and selling of all types of automobiles. It is one of the world's most important economic sectors by revenue. In the automotive industry it is practiced to reduce the cost which is associated to the development of products by sustaining a distinct design for a model. By taking advantage of common components, the company can take advantage over other. This can also be a risk for the company to lose the uniqueness of the product. The companies have to maintain their trade-off between reducing their development costs of the product to the degree of differentiation of that product.

The task of the automotive design team has three main aspects, interior design, exterior design, and color and trim design. Graphic design is also one of the important aspects of automotive design. Design not only focuses on the outer structures of automobile parts, but it also concentrates on the combination of shape and function. Integration of an automobile includes fitting of different parts to form different units and then mounting these onto the frame, forming the chassis.

An automobile skeleton basically comprises the following: 

The body shell, (skeleton of the vehicle).

The motor, (the internal combustion engine).

Transmission system (force from the engine to the wheels), which mainly includes components like gearbox, clutch, final drive and differential.

Suspension system (which connects the wheels to the chassis frame).

Steering

Electrical equipment

Brakes

The chassis is a complete road vehicle. It can now drive and organize itself just as in case of a car, the chassis is first tested on the road and then its complete body is attached, after this its ready to use.

1.1 History

In 18 century, with the invention of steam engine the history of automobiles revolutionaries. The first car was powered by a combustion engine which is running on fuel gas. The first motor vehicle was developed on the 4-stroke internal combustion gasoline-fueled engine in 1876. After this invention the first automotive firm in Europe and America was established. In late 19 century due to the development of steering wheel and floor mounted accelerator, the automotive industry speed up its development. During these time famous vehicle models "Ford’s Model T" was developed. (Source, Year)

During 20th century, in addition to new manufacturing practices and the development of technologies, societal infrastructure continued. Traffic lights and thousand of road signs started appearing over 100,000 miles of U.S roads. The famous assembly line Henry Ford’s was launched in these times, which helped the country economically and helped the mass production of vehicles. Some automakers merge with other companies to expand their market. (e.g. Chrysler and Dodge, Ford and Lincoln, Benz and Daimler). Adoption of such kind of new manufacturing process, mass production method had established the wide range of satisfactory cars to the society. (Source, Year)

GM adopted many strategies for producing variety of product while Ford worked on a single model, which help GM company to increase their market share. In the 1930s, different other vehicle brands take their places in market (e.g., Volkswagen, Lincoln Continental, and Ford Mercury). With this the new trends in Vehicle Preferences were established in American and European market. American society preferred luxurious and powerful car while European market was based on smaller and low priced cars. (Source, Year)

During World War II, these automotive industries were used to manufacture military vehicles and weapons. This war affects the economies of most of the countries such as Japan, European countries and some Asian Pacific countries. In result, it began development of new business strategies and productions. More innovative technologies such as fiberglass bodies, higher compression ratio fuels were established in late 20th century with impressive look, more comfortable and safe vehicles. (Source, Year)

Now a days, automakers have to identify more sophisticated and specialized automotive practices, which must cover all aspects like fuel, comfort, safety looks, speed, durability etc. China is appearing to be the most promising, on 2nd position its USA and then its Japan. And some of top rated motor vehicles manufacturing companies are GM, Volkswagen, Toyota, Hyundai Motors, Ford, and Nissan respectively, which includes Cars Light Commercial Vehicles, Heavy Commercial Vehicles and Heavy Buses. (Source, Year)

1.2 Problem Statement

This problem of this search is to explore the DSM technique. And to develop a methodology for the qualitative identification of collections of vehicle subsystems and components that comprise feasible platforms. The project will utilize Design Structure Matrices (DSM) to relate the subsystems in the automotive design.

1.3 Aims and Objective of the Research

This research is based on defining design envelope for automotive platforms; the rationale given provides the history and brief description on automotive industry and its platform. And farther objective of this search are as follows:

To investigate the subsystems of automobile.

To understand the concept of DSM.

Applying DSM to develop the methodology for qualitative identification of vehicle sub systems and their components that comprises of feasible platforms.

Advantages of using DSM in automotive industry.

To relate with few case study.

Some future advancement.

1.4 Research Questions

This study will try to clear the following research questions:

What are the factors involves in automotive industry and its platform?

What are the subsystems involve in automotive platform?

What is the concept of DSM?

What are the techniques used in DSM?

Why DSM useful in automotive industry?

How DSM useful in automotive industry?

What would be the further advancement can be made in this?

1.5 Importance of the Research

This research will provides the background and brief history on the automotive industry and its background. It will explain the DSM technique relatively in an easy way and its relation to the subsystem of automotive designs. The advantages of DSM techniques over other system.

Some case studies to help the topic understand better. Some future advancement which can be possible in the automation platform.

1.6 Structure of the Proposed Thesis

This thesis will be divided into five (5) chapters.

CHAPTER 1: This chapter will include the history and background of study, and will present research objectives, research questions and the significance of the study.

CHAPTER 2: This chapter will review of the design structure matrix.

CHAPTER 3: This chapter will describe the subsystem of vehicles using DSM techniques.

CHAPTER 4: This chapter will consider the analysis of the findings and hypotheses.

CHAPTER 5: This chapter will cover the discussion, recommendations, and further research areas.

Chapter 2

Design Structure Matrix

The organizations require some tools and techniques for the system decomposition and integration. A Design Structure Matrix provides a simple, straightforward, compact and flexible modeling technique that will support complex system more innovative solution. It provides the network modeling tools which represents the element of system and their interaction by highlighting the system architecture. DSM has many advantages including visual nature, intuitive representation, and powerful analytical capacity which led to their increasing use in a variety of contexts for example product planning, project development, project management, system engineering and organization design. (Source, Year)

2.1 Design Structure Matrix

(Source, Year)The DSM is a square matrix N x N, which maps the interaction between the sets of elements of N system. The benefit of the DSM over other network modeling methods is its graphical nature format of the matrix display. The matrix provides simple, compact and easy readable representation of system architecture. A simple example of DSM of a system with eight elements, along with its equivalent directed graph in figure. The cells are along the diagonal of the matrix which are easy to think in many ways. To make the diagram precise write the full name on the left side of the rows or can also be written above the columns. In this simple example the eight elements A to H, labeled both rows and columns A through H accordingly. Analyze row D, the inputs for element D is coming from elements A, B and F. these are represented by x mark in row D with column of A, B and F. Now look to the column E, E has the output going to A shown by the arrow in figure b and x in the column of E in figure a. This diagram gives you the interpretation of both inputs and outputs depending on its prespective provider and receiver.

2.2 Five Step Approach to Architectural Modeling and Analysis

DSM users are interested in exploiting the insights DSM which can provide the system improve understanding. For this purpose this five step approach is used for architectural modeling and its analysis. The five steps includes in this approach are: (Source, Year)

Decompose: Breaking down the system into its constituent element perhaps through several hierarchical levels.

Identify: Writing down the relationships between the system’s elements.

Analyze: Rearranging the system elements and their relationships for better understanding of structural patterns and the implications for system behaviors.

Display: Creating a impressive representation of the DSM model by highlighting different features of particular importance or of special interest.

Improve: Resulting in a better understanding of the system and also improved way to analyze and interpret the display.

2.3 Building / Creating the Design Structure Matrix

The achievement of the DSM approach is to determine the appropriate system decomposition and to get the accuracy of the system relationships which are collected. It is important first to decompose the system carefully and then to study the system elements (i.e. subsystems or modules). An appropriate decomposition can be recognized using two main approaches:

Converting the existing document into project schedules, design manuals, process sheets, IDEF models etc.

By structuring the expert interviews. (Source, Year)

The decomposition of system can be hierarchical or non-hierarchical (sometimes also called network decomposition). In the hierarchical decomposition, the system can be divided into sub-systems or modules and those modules are subdivided into other finer components. a system hierarchy is not evident in the network decomposition. Once the system elements or set of activities have been identified, they are listed in the rows and columns of the DSM model. In a task-based DSM, includes the minimum set of activities that are needed to perform a task before the activity under questioning can be started. In a parameter based DSM, the design parameter are rows and columns that are used to drive the design or to define the system. These parameters are marked by an 'X' or "●" in the DSM. (Source, Year)

After this, you can start redesigning it by using the different criteria described below.

Fig. Showing the activities included in a DSM-based project redesigning process.

2.3.1 DSM Partitioning

Partitioning is the process of reordering the DSM rows and columns in the new arrangement that does not contain any feedback marks.

into a lower triangular form. For complex engineering systems, it is highly unlikely to manipulate the rows and columns which will result in a lower triangular form. Therefore, the analyst's objective is to eliminate the feedback marks by placing the elements in diagonals as close as possible, forming a matrix for faster development process. (Source, Year)

The following are few approaches used for DSM partitioning.

Identifying the system elements that can be executed without other input in the matrix. It can be easily identified by observing empty rows in the DSM

Identifying the system tasks which will deliver no information to other elements in the matrix. It can be easily identified by observing an empty column in the DSM.

After steps 1 and 2 if there are no remaining elements in the DSM, then it is completely partitioned.

Determine the circuits by one of the following methods:

Path searching: the forward or backward information flow of a task if it’s not encounter twice. These tasks constitute a loop of information flow between first and second occurrence.

Adjusting the power in the adjacent matrix method, this will help in showing the element raise to reach into n steps by observing a non-zero entry along the diagonal of the matrix.

Eliminate the elements involved in a single circuit into one perspective element. (Source, Year)

2.3.2 DSM Tearing

Tearing is the process of removing feedback marks and then re-partitioning the matrix which will make the matrix a lower triangular matrix. These marks which have been removed from the matrix are called "tears".

First we have to identify the tears and set of assumptions to start our design iteration process. Design the set of assumptions in such a way that no more additional assumptions are needed. The are no such accurate methods exists for the tearing process but still try to use the following criteria to make tearing effective:

There should be minimal number of tears used, so that we can reduce the number of guesses.

Write those tears in the smaller blocks in the diagonals, so that if their exist iteration with in iteration block with in block we can solve those iterations.

2.3.3 DSM Banding

The collection of light and dark bands or levels in DSM showing the independency or levels this constitutes the critical path of the project. One element within every band is the critical activity, so for this reason fewer bands are preferred to improve the concurrency of the project. It is to be noted the feedback marks are ignore in determining the bands For example, in figure shown below, tasks 7 and 8 do not depend on each other for information, so therefore they belong to the same band. (Source, Year)

2.3.4 Clustering Overview

In partitioning, the main objective was to remove feedback marks along the diagonal, afterward the DSM elements will perform their task. Now the new goal is to find subsets of DSM elements which are known as clusters or modules, they are limited and less interactive. This process is referred as clustering. Clusters internally interact, in case of separate interactions it should be eliminated or minimized.

This figure shows two alternative clustering methods. The original DSM was arrange to contain maximum possible interactions between two separate blocks. For example AF and EDBCG, here three interactions are still outside those blocks. The alterative clustering blocks are better which includes almost all possible iterations. (Source, Year)

Clustering is sometimes the solution to tradeoff between the importance of capturing intra block dependencies versus inter block dependencies.

2.4 Types of DSM Models

There are four types of DSM within three main categories as shown in figure. (Source, Year)

The first category consists of statistic architecture models, these models represents those systems whose elements exist simultaneously. The applications in this category include Product architecture DSM and Organization architecture DSM. The architecture in which the components physically interact with one another is product architecture DSM. Organization architecture DSM is that in which members communicate with one another.

The second category is temporal flow model which represent system whose elements may be actuated over time. The application includes in this category is types of processes, it can be activity based models or low level parameter based models or can also be software processes.

The third category consists of multidomain matrix models (MDM), which represent more than one DSM model (e.g., product, process and/or organization) in just a single matrix. (Source, Year)

Summary and Concluding Remarks

The DSM method helps in major fields of engineering designs its management. The DSM is simple, straightforward and flexible modeling technique that will support complex system with the innovative solutions. DSM has many advantages including visual nature, intuitive representation, and powerful analytical capacity which increase variety of contexts.

This chapter includes the introduction and simple explanation on DSM. The simple five step approach to its architectural modeling for its understanding. Follow the steps includes in the creating the DSM, it helps you build a complete, accurate DSM model. In the end, the types of DSM are explained in the passage.