Thesis writing help uk
For example, the TransactionProcessor element was discussed in somewhat more detail than the order management system, but still not enough detail to be certain of its correct placement. For example, it might actually be hosted on one of the mid-range computers.
The general problem is that the data does not provide an exhaustive description each element. In interviews and documentation, architects tend to focus on elements that are particularly 81 5 Case study: Architecture evolution at Costco salient, at the expense of more peripheral elements.
With more time, I could have remedied this through follow-ups with the study participants. But the difficulty of getting an accurate and comprehensive picture of an architecture also suggests opportunities for future research into methods of architecture elicitation. How can we adequately capture the point that there are hundreds of individual warehouses across the country?
In an intermediate state, there is no good way to show a transitional point in which some warehouses are using a legacy system and some others are using its modernized successor. In the model in figure 13,1 showed these ancillary systems as being fully integrated through the integration architecture, but there are other thesis writing help uk possibilities that might be just as likely.
To some extent this kind of uncertainty is unavoidable, but it also suggests the possibility of capturing the uncertainty in the model itself and reasoning about the trade-offs among different possibilities.
In formal architecture description, we are very precise about how we describe relationships among elements. Formally, to say that a controller is connected to a mid-range computer is different from saying that the point-of-sale system hosted on that controller is connected to a socket server hosted on the mid-range computer. In everyday language, though, these can amount to the same thing. One way of understanding such examples is as instances of a very common linguistic phenomenon called synecdoche, in which a part of something refers 82 5. There are other ways in which casual language treats thesis writing help uk architectural structure imprecisely. In the content analysis, I identified this as a connector between the point-of-sale system and the CRM system. Such complexities suggest a need for further research on how humans talk about architecture and how to elicit precise architectural information from practitioners. Connecting the point-of-sale system to a new system 3.
Doing in-house customization of an off-the-shelf point-of-sale system 4. Paying the vendor to customize an off-the-shelf point-of-sale system 5. Upgrading the operating system of the warehouse controllers 6. Deploying new point-of-sale software to the warehouse controllers 7. Installing an off-the-shelf product in the warehouse 10.
Replacing the data queues used by the socket server with message queues 13. Because of the scale and complexity of the point-of-sale evolution, a fairly large number of operators would need to be defined to accomplish this. But the operators mentioned in the data are a good basis on which to evaluate our modeling approach. These operators are likely to be no less complex and no less difficult to model than typical evolution operators. Connecting the point-of-sale system to a new system amounts to the creation of a new connector between the point-of-sale system and the new system.
To avoid ambiguity, the operator must take as parameters the specific ports to join, rather than just the components.
Even the operators that seemed conceptually complex turned out to be simple to define. Although we should be careful of drawing too strong a conclusion from this limited sample, this suggests that the operators that arise in real-world evolution may tend to be fairly simple in many cases, and that operator specification is not as difficult as might be feared.
Suppose that we were interested solely in the reliability of the controllers in the warehouse. A warehouse has two redundant controllers: a primary and a fail-over. We can annotate each of these two components with a property indicating its expected failure rate (e. But it is a reasonable simplifying assumption for our demonstration here. That is, avoiding disruption to users has a great thesis writing help uk deal to do with the specifics of exactly how the change is thesis writing help uk carried out, and details like user interface elements, and not much to do with architectural structure. In fact, the same architect made a similar point later in that interview, noting that carrying out the evolution would require attention to minute, nonarchitectural details such as the color of the labels on the keys of the cash registers: The things that boggle my mind we talk about in this project—well, we need to know what color code to put on the key cap. I say, oh, yeah, I never really thought about that. So you learn a little bit more every time you turn around.
The most straightforward way to model this constraint is as a precondition on the operator that would modify the certified equipment. For example, if we have an operator such as modifyCashRegisters, it should have as a precondition that the recertifyEps operator has already happened to ensure that the modifications to the cash registers have been approved. However, if we enriched the architectural model with multiple warehouses, this would be straightforward to model. In many cases, there was some degree of choice in representing the constraints. Ordering constraints, for example, can typically be represented either as evolution path constraints or as preconditions. What is important is the overall result: all the architectural constraints captured in the content analysis are representable using our approach, albeit with varying degrees of difficulty. We have seen some specific areas where our constraint language might be able to benefit from further enrichment, such as support for reasoning directly about the transitions in an evolution graph in addition to the states.
But we did not encounter any architecture evolution constraints that could not be modeled 87 5 Case study: Architecture evolution at Costco at all. Most of thesis writing help uk these can be modeled as evaluation functions with little trouble. Of the seven dimensions of concern identified in the content analysis, five can be modeled as evaluation functions with little trouble.
In our approach, cost can be modeled as a property of operators.
Each operator can be assigned a property describing its estimated cost in dollars. Then, an operator analysis can simply add up all the operators within an evolution path to get an estimate of the overall cost of the path. There is a very large body of work on cost estimation in software engineering, so we may simply assume that the costs of the operators can be determined through traditional methods. Two of the dimensions of concern are not so easy to model. One concern identified by the content analysis pertains to low-level implementation details not relevant to an architectural analysis. However, the other, flexibility, is a genuine architectural concern that cannot be easily analyzed using our approach. System flexibility is quite difficult to estimate based on an architectural model.