Surface mount technology, pcb, ems electronics assembly of printed circuit boards site covering electronics manufacturing assembly process from concept to design.Paper for Topic Requirements Specifications.Carnegie Mellon University 1.Dependable Embedded Systems.Spring 1. 99. 9 Author Eushiuan Tran.Defining requirements to establish specifications is the first step in the.However, in many situations, not enough care.This causes problems.Therefore, it is necessary that.This difficulty in.A Field Study Of The Software Design Process For Large Systems' title='A Field Study Of The Software Design Process For Large Systems' />About SEI.The SEI helps advance software engineering principles and practices and serves as a national resource in software engineering, computer security, and.The difficulty arises from the fact that establishing requirements is a tough.In addition, it requires people with both communication and.As requirements are often weak about what a system should not.The development of dependable embedded systems requires.Therefore, the importance of.Contents Introduction.Requirements and specifications are very important components in the.Requirements analysis is the first step in.While it is a common.For activities in this first stage has.Design Systems, Inc.Concept to Commission services for the automotive, food and beverage, pharmaceutical, package.For. example, errors developed during the requirements and specifications stage may.When this error is discovered, the.This leads not only to more time wasted but also the possibility of other.Many accidents are traced to.While these problems may be acceptable in.Therefore, it is necessary that the.There is a distinct difference between requirements and.A requirement is a condition needed by a user to solve a.A specification is a document that specifies.For example, a requirement for a.The specification.Another term that is commonly seen in books and papers is requirements.It includes functional requirements, performance requirements.So the. requirements specification is simply the requirements written down on paper.Key Concepts. Establishing Correct.Requirements. The first step toward developing accurate and.As easy as this. sounds, establishing correct requirements is extremely difficult and is more of.There are different steps one can take toward.Although some of the suggestions sound.The first step is to negotiate a common understanding.There is a quote.John von Neumann that states Theres no sense being exact about.Gause. 89. Communication between the designer and customer is vital.There is no point in.Problem stems from ambiguities in stating requirements.For example, say the.Boston to Washington D.C. Possible interpretations of this.Although each of these transportation devices satisfy the.Ambiguous requirements can be.The. above requirement does not state how fast the people should be transported from.Boston to Washington D.C. Taking an airplane would certainly be faster than. Phonics Made Easy Flash Action School . These are also missing requirements.What. exactly does group implyA group can consist of 5 people, 1.The requirement states to create a means.This is an example of.It. is important to eliminate or at least reduce ambiguities as early as possible.Often the problem one has in establishing correct requirements is how to get.One of the most important things in getting started is to ask.Context free questions are high level questions that are posed early.Examples of context free questions include who.These questions force both sides, designer and customer, to look at.Also, since these questions are appropriate for any project.Another important point is to get the right.There is no point in discussing requirements if the.Related to getting the.Having effective meetings is not.However, since they play a central role in establishing.There are. important points to keep in mind when creating effective meetings, which.Gause. 89 Exploring the possibilities is another important step toward generating.Ideas are essential in establishing correct requirements.Every. project will also encounter conflicts.Conflicts can occur from personality.It is. important that a facilitator is present to help resolve conflicts.In establishing requirements, it is important to specifically establish the.Usually in the process of gaining information, functions are the first.Functions describe what the product is going to accomplish.It is also important to determine the attributes of a product.Attributes are. characteristics desired by the client, and while 2 products can have similar.After all the. attributes have been clarified and attached to functions, we must determine the.Preferences, which is a desirable but.Finally, we must determine what the clients expectations are.This will largely determine the success of the product.Testing is the final step on the road to establishing correct requirements.There are several testing methods used, as listed below.Gause. 89 Ambiguity poll Used to estimate the ambiguity in a requirement.This involves asking questions such as how fast, how big, how expensive, and.Technical review A testing tool for indicating the progress of.It can be formal or informal and generally only deals.Technical reviews are necessary because it is not.User satisfaction test A test used on a regular basis to.Black box test cases Constructed primarily to test the.Existing products Useful in determining the desirable and.At some point it is necessary to end the requirements process as the fear of.This does not mean that it is impossible.However, it is important to end the process when all the necessary.Establishing good requirements requires people with both.Technical skills are required as the.Communication skills are necessary as there is a lot of exchange.Without either of these.It is essential that requirements in safety critical embedded systems are.The problem with requirements is that they are.In a dependable system, it is.These systems have an even greater urgency that.Requirements with no ambiguities will also make the system more.Extra requirements will usually be required in developing a.For example, in developing a dependable system.Requirements and.Specifications Role in System Design.Systems exist everywhere in the universe we live in.The universe can be.A system is very loosely defined and.Blanchard. 90 A combination of elements forming a complex or unitary whole i.A set of correlated members i.An ordered and comprehensive assemblage of facts, principles, or doctrines.A coordinated body of methods, a complex scheme, or a plan of procedure.Any regular or special method of plan of procedure i.The important characteristic of a system is that there is unity, functional.Systems engineering is not a technical.Blanchard. 90 Systems engineering requires knowledge.The development of embedded systems.Therefore, it is appropriate that.The conceptual system design is the first.Figure 1. Each individual box will be explain.Figure 1 Example of system requirements definition process Blanchard.In establishing system requirements, the first step is to define a need.This need is based on a want or desire.Usually, an individual or organization.After a need is defined, feasibility.The system operational requirements should also be defined.This. includes the definition of system operating characteristics, maintenance.In particular, the system operational requirements should include the following.Blanchard. 90 Mission definition Identification of the primary operating.Performance and physical parameters Definition of the operating.Use requirements Anticipation of the use of the system.Operational deployment or distribution Identification of.Includes quantity of equipment.Operational life cycle Anticipation of the time that the system.Effectiveness factors Numbers specified for system requirements.Includes cost system effectiveness, mean time between maintenanceMTBM.Environment Definition of the environment in which the system is.Basically, the system operational requirements define how the system will be.Usually, in defining system requirements.However, this means that emphasis is only.It is essential to take.The. system maintenance concept basically describes the overall support environment.After the system operational requirements and system maintenance concept are.The following process is.Blanchard. 90 1. Define the problem The first step always begin with.Identify feasible alternatives All the alternatives should be.Select the evaluation criteria The criteria for the evaluation.Applying modeling techniques A model or series of models should be.Generate input data The requirements for appropriate input data.Manipulate the model After data is collected and inputed, the model.Analysis after using the model will lead to recommendation for.After the preliminary system analysis, advanced system planning will be done.Early system planning takes place from the identification of a need through the.