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uml case study

View the complete E. Coli Fermentation Development case study (pdf) Analytical Development and Characterization. A variety of state-of-the-art tools are used to characterize the recombinant protein GPIB-FC in order to understand the basis of aggregate formation. The Role of . UML (Unified Modeling Language) is a standard language for specifying, visualizing, constructing, and documenting the artifacts of software systems. UML was created by the Object Management Group (OMG) and UML specification draft was proposed to the OMG in . The problem with many Unified Modeling Language (UML) educational texts is that they present the various concepts each in isolation; so you see a use case diagram for one problem domain, a class diagram for an entirely different problem domain, and you never get to see the important traceability between the diagrams. In this case study we aim to put it right by working through a single problem.


End-to-End UML Case Study for a Stock Broker


The problem with many Unified Modeling Language UML educational texts is that they present the various concepts each in uml case study so you see a use case diagram for one problem domain, a class diagram for an entirely different problem domain, and you never get to see the important traceability between the diagrams.

In this case study we aim to uml case study it right by working through a single problem from use cases and activity diagrams, through sequence diagrams and state diagrams, uml case study, to class diagrams and component diagrams.

We have arranged the case study as three distinct perspectives or aspects as follows. The functional aspect: comprising UML use case diagrams and activity diagrams. The behavioral or dynamic aspect: comprising UML sequence diagrams and a state diagram. The logical or static aspect: uml case study UML class diagrams and a component diagram. The challenge with any such case study is to find a problem that is sufficiently challenging, sufficiently realistic, yet self-contained and simple enough to present in a single document.

The problem domain should be familiar to most readers while providing sufficient scope for us to explore a range of UML concepts and constructs. Each function will be represented as a UML activityand will then be further decomposed where appropriate into a number if inter-related UML use cases, uml case study.

At its simplest level we can visualize the process as two parallel streams or swim lanes of activities as shown in the partial activity shown below. The Investor is able repeatedly to Place [an] Order Instruction to buy or sell shares, uml case study, with each one of the order instructions being recorded in the Order Book.

It is debatable whether this overarching process is infinite or whether the two parallel streams of activities must at some point be synchronized and must lead to a final activity. This moot point adds little or nothing to our understanding of the process, and we can make best use of our time by moving to the next stage of our analysis: the use case diagram. In the use case diagram shown below, you can see how the names of our actors — Investor and Stock Broker — mirror the titles of uml case study swim lanes shown on the earlier activity diagram.

You can also see how the significant use cases — Place Order Instruction and Execute Orders — tie up with the key activities shown on the activity diagram. Such traceability between UML diagrams is important yet often overlooked.

Whenever an Investor decides to Place [an] Order Instructionhe or she must Select [a] Stock to trade, and this is irrespective of the specific kind of order instruction that will be placed, uml case study.

We can think of these variations as extensions — or possibly specializations — of the Place Order Instruction use case; hence their representations as extension use cases in the diagram above.

This would be a matter of personal uml case study and the overall semantics of our use case model would remain roughly the same. Each use case will be described ultimately by a use case specification written in prose, uml case study, and we should guard against decomposing the functionality to the extent that there are numerous use case specifications with each one containing just a single sentence.

Here we present the written use case specifications using a standardized use case specification template. Notice how certain key terms have been emboldened with a view to these becoming candidate object entities and data items. Actor s. Basic Flow. Alternative Flow. At step 2, uml case study, the actor can click the Cancel button, uml case study, in which case a NULL stock symbol is returned in step 3.

This use case allows the Investor actor to place an order instruction in the order bookto be executed subsequently by the Stock Broker. If the actor fails to choose a stock i. Extension 1. Extension 2. Extension 3. Upon completion, a new Order instruction must have been added to the Order Book.

Since no additional actor interaction is required, it is debatable whether a specific and trivial extension use case is required rather than simply including this step uml case study the Place Order Instruction main flow. This use case has been included in our case study, both to stimulate such debate and for consistency with the other extension use cases — i. Special Requirements. In step 2 of the basic flow: not only must the price be crossed in the right direction depending on the type of order stop order to buy, stop order to sell, limit order to buy, or limit order to sell but also there may be regulatory requirements or an order execution policy that dictates when an order should or should not be marked for execution.

These matters do not affect the basic flow, but do impact the coding of whatever object method is used to implement step 2. In this section we have devised a UML activity diagram to represent a simplified version of a typical stock brokerage process; and in doing so we have identified the main actors Investor and Stock Broker and their activities Place Order Instruction and Execute Orders, uml case study.

For each use case, we have written a use case specification using a standardized template. We have used a range of optional template sections including Alternative Flow, Extension, Post-Conditions and Special Requirements where appropriate. While some aspects of this case study have been contrived to show off the range uml case study analysis tools at our disposal, it is nonetheless representative of a system that realistically could be implemented… and which we will go some way towards implementing in subsequent sections.

Whereas use cases are inherently non-object-oriented, the state diagram s and sequence diagrams presented here are object-oriented, uml case study. While it is perhaps more usual to draw UML uml case study diagrams that realize use cases before drawing state diagrams for individual objects, this is not mandatory.

For the purposes of this case study, it is useful for us to present a UML state diagram in the first instance so that in due course we can highlight the important traceability between this diagram and the first of our use case realizations. We only need to draw state diagrams for entities or objects that have meaningful stateful behavior, and which respond to events in different ways according to their states. Uml case study Order Book has meaningful stateful behavior, and it responds to events in different ways according to its states as you can see here….

This state diagram was devised by taking a step back and thinking in a use-case-independent way about how we would expect an Order Book entity or object to behave. We concluded the following:. In terms of traceability, this use-case-independent assessment of the Order Book expected behavior uml case study already highlighted a potential correction to our original use case specifications.

Since we can only execute orders when the Order Book is Populatedshould this not be a pre-condition of the Execute Orders use case specification? The software architect has told us that each use case will be represented in code by a Controller class, uml case study, so our realization begins with the StockBroker actor notionally running the ExecuteOrders controller.

The remainder of the use case realization follows the use case specification text. Step 1 of the basic flow tells us that steps 2 and 3 will be repeated, and in this case we indicate the repetition using a simple note alongside the executeOrder orderN message that we intend will execute the N th order in the OrderBook. A picture is worth a thousand words, and here is the pictorial representation of the sequence just described. We are not merely executing and removing any old order, but specifically the N th one.

Sequence diagrams are usually kept simple and linear, uml case study, with little or no use of conditional behavior. In this case, uml case study, we have shown the scenario in which it is true that uml case study Order isExecutable so that we can execute it.

The alternative scenario is trivial and would not normally require an entirely separate sequence diagram, although it would not be wrong to draw one. By taking this further we can note that while this use case realization takes account of the executeOrder event and the removeOrder action shown on the state diagram, it does not account for the addOrder event. In our case study, the only use case that is initiated directly by the Investor actor is the Place Order Instruction use case that we realize using a sequence diagram as follows.

You should see how the interactions reflect the steps of the basic flow within the use case specification. In reality, we — and crucially uml case study software developers — can infer the other realizations from this single model realization.

While we see this linkage as the first uml case study in uml case study sequence, we should keep in mind that the reusable Select Stock use case controller might be invoked by other use case controllers in future scenarios. The sequence proceeds according to the use case specification such that the StockList is displayed, the Investor in this uml case study actor selects [a] stock from the list, and the relevant stockSymbol is returned to the SelectStock use case controller which in turn passes it back to the invoking use case.

It shows the context in which the addOrder message or event will be uml case study to the OrderBook object; this linkage having been unresolved up to this point. This realization is also useful in helping us to determine what information needs to be passed as parameters in the run … operation of the PlaceAtBestInstruction controller and the constructor of the AtBestOrder entity. Once the Stop Order is created, it is added to the OrderBook in the final step, uml case study.

We will return to this idea when discussing the logical or static aspect of our case study in the next section, uml case study. The only difference is that a LimitOrder instance rather than a StopOrder instance would be created in the penultimate step, but would once again be added to the OrderBook as a generic Order object.

Challenge for the reader: do you uml case study anything missing from this diagram? The clue to what is missing is in the first step of the basic flow of the Specify Target Price use case, which was…, uml case study. In a further refinement of this sequence diagram, the analyst should clarify that the display operation of the TargetPriceForm takes a custom message as a parameter; like this…. In this section we have used UML state diagrams uml case study sequence diagrams to model the behavioral or dynamic aspects of our case study.

Most importantly we have highlighted the fact that each event shown on a state diagram must be present on at least one sequence diagram; otherwise there is no context i. This traceability may be important in helping us to determine if all of the systems functions i. The purpose of drawing the use case realizations is to make the important transition from the uml case study world of the process analyst or functional analyst to the object-oriented world of the software development team.

UML state diagrams and sequence diagrams may be drawn at various levels of abstraction, with the ultimate aim being to provide a set of artifacts that programmers can use to code the behavioral aspects of the system.

In this section we describe the logical relationships and dependencies between the business entities and other object classes such as user interface elements that will implement our software solution. We use UML class diagrams to show uml case study combinations of object classes participate in each use case, and we further use class diagrams to show the static structure and relationships in a use-case-independent way, uml case study.

We use the UML component diagram to show how classes will be packaged for deployment, uml case study. In the course of devising the use case realizations as sequence diagrams previous section we have gained a significant head start in identifying the object classes that the software development team will need to code in order to implement the software solution.

For the purposes of this case study we will construct a selection of participating class diagrams that complement the more involved i. These class diagrams are also intended to show off various UML constructs including association, aggregation, uml case study, dependency and generalization.

Whenever a message is sent from one object to another in a sequence diagram, it implies either a transient dependency dashed line or a persistent association solid line between the two object classes. In the participating classes diagram below, you can see that the ExecuteOrders controller class is dependent on the Uml case study class to the extent that it cannot function without the second class, uml case study, but there is no persistent relationship as might be recorded in a database between the uml case study classes.

In contrast: the OrderBook class is related to the Order class via the strong form of association known as aggregation shown as a hollow diamondsuch that we must record in a database the fact that the OrderBook contains a specific set of Order s. The multiplicities on uml case study aggregation line indicate that the OrderBook can contain zero or more Orders i.

While constructing this participating classes diagram we have taken the opportunity to add more detail. So whereas the original sequence diagram included an executeOrder message with an un-typed orderN parameter, in the class representation of the OrderBook we have now assigned the parameter the type of int integer, uml case study, or whole number to yield the complete operation signature of executeOrder in orderN : int.

As well as showing dependency relationships, this diagram also shows a dependency between the specific Stop Order class mentioned in step 2 of the use case basic flow and its more generic Order representation mentioned in step 3. Whereas this generalization relationship was implied in the use case text and the use case sequence diagram, here we formalize it using UML.

We have also used this particular class diagram to illustrate something else. Whereas in the previous class diagram we introduced the notion of including operations within the bodies of classes on a class diagram, on this diagram we have introduced the notion of including attributes. Whereas all stock Order instructions must record a stockSymbola numberOfSharesand a buyOrSell indicator, uml case study, not all order types include the targetPrice attribute that is specific to a StopOrder and — as it happens, uml case study, and although it is not shown here — a LimitOrder.

Our mentioning of the various order classes, and their relationships to the generic StopOrder class, causes us to think uml case study additional class diagrams that show interdependencies and relationships in a use-case-independent context, uml case study. This is our next theme. For example, the class diagram for the Place Limit Order Instruction use case would be practically identical to that of the Place Stop Order Instruction use case. In the two examples that follow, we use class diagrams respectively to clarify the generalization inheritance structure of an individual class and to document the interdependencies between user interface classes controllers and forms in a use-case-independent context.

UI Dependencies Class Diagram, uml case study.

 

“UML(Unified modeling Language)”: Case Study

 

uml case study

 

Case Study: Are Microfiber Mops Beneficial for Hospitals? This is a reprint of a study Prepared by: Jennifer Desa, Anila Bello, Catherine Galligan, Tom Fuller, and Margaret Quinn. This document describes UML versions up to UML and is based on the corresponding OMG™ Unified Modeling Language™ (OMG UML®) specifications. UML diagrams were created in Microsoft® Visio® using UML 2.x Visio Stencils. You can send your comments and suggestions to webmaster at [email protected] UML (Unified Modeling Language) is a standard language for specifying, visualizing, constructing, and documenting the artifacts of software systems. UML was created by the Object Management Group (OMG) and UML specification draft was proposed to the OMG in .