Design Automatic Control System.
Functional Analysis and Synthesis
Michael V. Tokarev, PhD, Vladimir Meldov, Corporation AXIS Ltd., February 2013
S.-Petersburg, Russia
PACS 02.30.Sa
Introduction
The article discusses the method of transition from business processes to be automated with the help of Automatic Control System (ACS) to elements to future automated system. It is well known that the objective of ACS is to automate it functions performed in enterprises within specific business processes. We do not consider cases where business processes in enterprises are not defined. It is assumed that before the automated management of the company (or division) the optimization of business processes to not automate nonformalized processes, as it always leads to failure of automation itself.
There are 3 main challenges in the transition from business functions to the automatized functions:
1. no special knowledge of information technology from the owners of business processes;
2. no special knowledge of business processes (or lack of knowledge) and IT professionals involved in automation;
3. lack of sufficient will guide enterprises (units) in the successful implementation of business process automation;
4. no specific comparison methodology functions of business processes and functions of the ACS.
Since in this article we have no way to influence the first 3 difficulties (as they are organizational), the purpose of this article is a better understanding by designers of automated systems of this crossing comparison methodology functions of business processes and ACS.
Though it may seem strange, but most of the work designers (adopters) learned to perform in the first place thanks to the ready-made software solutions. At first glance, all automation projects to be successful. But that's over the display functions on a set of functions ACS nobody seriously thinks. As a result, according to various experts from 30 to 90% of the projects end failure.
The life cycle of ACS
In order for to understand the context in which we work, we present the basic terms and concepts.
Automated (computer-aided) system - a system that includes the information infrastructure, personnel, and rules under which personnel interact within the system.
Business process - a certain sequence of functions controlled by a single owner and using resources in their activities in accordance with certain rules.
Life cycle - the time period (stage) of the automated system on its ideas and implementation to its cancellation. The main stages of the automated system in our definition are:
• Identification of system requirements;
• Systems Design;
• Engineering Design;
• Implementation;
• Pilot Operation;
• Maintenance of the System.
If most of the work on each stage to determine standards and requirements for documentation, the actual transfer of the functions of business processes to the functions of process control is usually performed by specialists in accordance with the experience of a particular person or not performed at all, on the assumption that "and so all clear. "
However, we believe that this transition is the key, and if not properly performing his functions automated system will perform "internal problems" ACS, not meet the goals of the business processes for which ACS and originally designed. No number of such systems in practice, the objectives set not target business processes (or enterprise) and "automation" by itself or "the implementation of software features," or, even worse, private purpose IT and CIO (Chief Information Officer).
At the stage of System Design developer should analyze all functions of the enterprise (business process) to propose a draft automated system to match it with the management of the enterprise. And there's always a collision, because "the company's management," as a rule, does not understand the functions of the automated system. In practice, management signed the Terms of Reference, based on the opinion of the CIO or none at all based on someone's opinion, considering that he has enough knowledge. Later, after the implementation of the system, it appears that not all functions of the company or some of the functions are automated computerized wrong. Resources spent, time is lost, we have to accept the fact that there is.
Analysis and synthesis functions of the enterprise
Once again, we note that all the arguments were about companies where the optimization of business processes performed. There is a description of them, appointed by the owners, describes resources. Otherwise, talk about automation does not make sense.
So, we have the business processes specific company. Their degree of formalization may be different, but it does not really matter, what matters is that there is a process owner, and resources (especially human).
After the company's management decided to automation, we have, at least, of the business processes that are supposed to be automated. Below we show practical examples of analysis and synthesis functions of business processes and process control, and here try formally present the outcome of the designers.
b = {C, R, F}, b - a specific business process is defined as a triple of C - the process owner, R - Resources and F - functions of the process,
b Î B, where B - the set of business processes specific enterprise,
r Î R, C Î R, where R - lots of resources, including human,
f Î F, where f - any function that runs on the company from the set of functions F.
Thus, in the functional context
bj = S fij, for i = {1, 2, ... n}, j = {1, 2, ... m}, with fij can be both unique and repeated within the same process or in different processes. For example, the statement (signed) documents leader in all business processes are executed the same, but before signing the document may take a variety of a negotiation and the signing document can go to various departments (divisions). Actually the same "signature" means an authorized person approving signature on a paper document.
So, when deciding to automate business processes m, we get the matrix:
f11 f21 ... fn1
f12 f22 ... fn2
............
f1m f2m ... fnm
As already noted, the functions fij are unique or similar in nature.
After receiving the full matrix of functions, the designer must perform the analysis in order to identify similar algorithm execution and essentially functions. How to be conducted this analysis?
1. Identified of the same functions: by name, by place of performance, by resources, by the domain and range of values of sub-functions of weight function (value), run-time, the possibility / necessity of automation;
2. It turns out the possibility of combining similar functions is to optimize business processes, and resources in order to unify and solvers (tools and a certain level of staff training). If the function can’t be combined, it is decided that it is not the same (unique) functions;
3. Building a new matrix of unique features, performed functional synthesis. The result of this work can be presented in a matrix identical to the dimension (for each business process), with the same function are appropriate identification.
At the end of this phase, we obtain the matrix of unique features in the context of business processes (domain) of the enterprise.
As an example, the "Print the document". This seal can be performed as a typist on a printing press, local printers, network printer, automated (initiated by staff), automatically, etc. All of these features are different in nature to the criteria listed in paragraph 1. On the other hand for information in business processes can be the same, for example, by mail, and the output flow of information produced in the form of hard copies of the documents carried by couriers between units.
Mapping Functions
Next, the designer of each unique features of the domain to the function to be executed by means of an automated system. Those functions that are not intended (or impossible) to automate extracted from the matrix and further design of ACS should be organized interface of the ACS to the functions (the system must give out the input values for these functions, and / or pick up the results of the execution).
On completion of this phase, we obtain a matrix of larger dimension (three-dimensional), as part of the unique features of a business process can only be performed in several roles within the automated system.
For convenience, we can design a three-dimensional matrix to transform into a linear sequence of functions, each loaded the third symbol index.
Since we have already moved away from the functions of business processes, will be discussed further on automated functions
aijk, with i = {1, 2, ... n}, j = {1, 2, ... m}, k = {1, 2, ... p}, where
aijk Î A (A - many functions automated system).
Synthesis of automated functions
The resulting matrix (or linear list) automated functions, they must be combined, in terms of the criteria already automated system, namely, the possible tools (printer, network components, computer, etc.), operators, resources, suppliers and consumers of information, the location of devices and consumers, quality of information, environmental conditions, the load on the infrastructure elements.
According to the results of synthesis of the designer gets the composition of infrastructure needed to perform these functions.
Further work on the design of ACS conducted in a manner as determined by the applicable standards or internal procedures the manufacturer. In particular, it must be determined for future automated system morphology (structure elements, the connections between them, the boundaries of the system and network communications with external entities).
Conclusion
As mentioned above, the real analysis and synthesis functions domain companies are generally not satisfied at work on automation. Not carried out and the following stages of analysis and synthesis of automated functions. It is the failure of these important stages of work on the system design stage and leads to incorrect automation of work from the point of view of the consumer, that is, plant personnel at all levels.
Once again the stages of work that must be performed on the stage of system design:
1. analysis and synthesis functions of the enterprise;
2. mapping functions;
3. synthesis of automated functions.
The last decade of widely developing universal software products designed to eliminate many of the errors of designers and developers of automated systems. Most serious vendors provide their own implementation methodology universal products, but most of these techniques are omitted stages of functional analysis and synthesis in the assumption that such universal software (and embedded in ACS “software applications”) can satisfy the majority of existing enterprises. This leads to the fact that companies are forced to go to the introduction of automated systems to change business processes, "adjusting" for the algorithm, which is proposed vendors. Only a small number of companies to start implementing ACS the reorganization business processes with potential for automation. Automation is all the company can’t be an objective of this work, although almost all the projects it is this goal and put implementers.
It should be noted that such a science as General Systems Theory and its Systems Engineering section clearly and specifically defines as the use of targeting systems and methods for morphological analysis. Widespread use of the terms "systems analysis" and "systems approach" should be based on a least the methodology for such work.
References
Bruk V.M., Nikolaev V.I. System Engineering: methods and applications, (1985), S.-Petersburg, Russia, Mashinostroenie.
Tokarev M.V. System approach to design information systems, (2011) Conf.: “System analysis and information technology” v.2. Cheliabinsk, Russia, p. 75-77.
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