Modern complex technical systems (CTS) consist of many distributed components that receive, process and transmit information. The interconnection between subsystems and elements is the enterprise information system (EIS). Nowadays, this system uses elements that are heterogeneous in composition and functional purpose, large amounts of resources (including material and information) to maintain or improve the quality of functioning (implementation of supported business processes (BP)) and development at each stage of the life cycle of the CTS. To improve the effectiveness of achieving and solving strategic and local goals and objectives of systems, it is necessary to create models that allow to describe the processes of their dynamic adaptation (integrated modernization). It is necessary to develop integrated methods, algorithms and techniques that will allow to fully and proactively control both the processes of functioning and modernization of the EIS in order to increase the efficiency of the BP. This article presents an approach that allow to analyze the structural and functional appearance variants of the implemented EIS and synthesize schedules and plans of its joint functioning and modernization. An illustrative example is given.
The EIS is the core of critical infrastructure
objects. It is an environment for the creating,
transmission and analysis of control actions in
an information space [
CEUR Workshop Proceedings (CEUR-WS.org)
Constantly changing requirements for technological, technical and information processes, caused by poorly predicted external and internal impacts on the BP, force decisionmakers to conduct continuous reengineering and modernization of the EIS.In practice, we observe • the increase in the number of element refusals and EIS subsystems; • delays of synthesis and control programs; • the increase in consumption of all resources connected with the implementation of the target, providing and supporting operations.
Today, BP, associated with the widespread
use of high technologies, are more than ever
dependent on the rational organization of the
information infrastructure as the quality of
functioning and development (modernization)
decreases.) EIS can lead to disruption of the
implementation of the strategic goals of the
CTS [
This paper is devoted to the proactive search for the appearance of the new information system being implemented and ways of synthesizing integrated plans and schedules for modernization “old” EIS.
It should be noted that researchers observe
a unique attitude of decision-makers to the
deployment, support and optimization of
information infrastructure. Managers are
focused on minimizing the implementation
time, simplicity of the user interface, minimum
cost of the implemented equipment, without
taking into account direct and indirect
expenses for further maintenance [
Another important problem is the
orientation of the relevant design solutions for
complex systems only to meet the standard
reliability indicators. This approach does not
allow us to scientifically and reasonably
optimize the resource expenses for technical
solutions. The analysis of modern methods and
algorithms of solving problems of optimizing
reliability indicators of the CTS has shown
that most of the developed methods and
algorithms are aimed at solving
singlecriterion and two-criteria problems of
choosing the composition of elements and
subsystems [
A number of approaches has been developed to solve the problems of integrated planning and scheduling of the functioning and development of the EIS. Traditionally, they are based on the methods of the scheduling theory and linear, discrete, stochastic programming. Analysis of modern software and mathematical support of decision support systems and PLM-systems, showed that it cannot effectively and reasonably solve the problems of automated synthesis of the appearance of the implemented information system, as well as integrated plans for the functioning and development of the EIS, which exclude the shutdown of BP.
In addition, we present brief results of the
analysis of integrated planning and scheduling
tasks the CTS functioning and modernization.
Thus, synthesis of the rational modernization
plans of the EIS is connected with the search
for joint solution of the following main tasks:
1. the synthesis of structural and
functional appearance of the upgraded
system;
2. the timing of completion of the
modernization;
3. the synthesis technology
modernization;
4. the synthesis of the joint functioning
and modernization plan;
5. the synthesis of control inputs,
ensuring the implementation plan and
scheduling of modernization [
scheduling models
The authors refer the tasks of determining the list of the implemented elements of “new” EIS and synthesizing integrated programs of joint legacy EIS modernization and functioning to the most important problems of planning and scheduling the development of information systems. This article presents in a generalized form models for the synthesis of the appearance of the “new” EIS and the development of comprehensive plans for the relevant modernization works for legacy system. At the first stage of research, we will focus on the problems of determining the hardware composition of the implemented system for a given architecture. The second stage will be devoted to the searching for a rational plan for the joint functioning and modernization of the EIS elements and CTS subsystems.
Structural analysis of the functioning of the
EIS (Fig. 1.) within a given architecture begins
with the construction of a functional integrity
scheme [
During its development, the logical conditions for the implementation of its own functions by the elements and subsystems of the object are graphically described, as well as the goals of modeling are indicated. Figure 2 shows a diagram of functional integrity. the set of existing legacy EIS elements and “new” EIS ( Bij - j - Ai type of the EIS element). PF ({ pi , qi = 1 − pi}, i N ) probabilistic function of failure-free operation of elements for the implementation of the operation modes of the legacy EIS and “new” elements specified by the logical criterion F . cij , i N , j {1, 2,..., mi} is the cost estimation of used elements during a given lifecycle period; ij ,i N , j {1, 2,..., mi} a number of implemented EIS elements of each type. pij ,i N, j {1, 2,..., mi} is the probability of failure-free operation of legacy and “new” EIS elements.
The variant of designed EIS is X = xij where xij = 1 if instead of Ai the element of type is used, then in the other case Bij
n mi xij = 0. C( X ) = cij xij is the cost i=1 j=1 estimation of the project variant of the n mi developed EIS. V ( X ) = ij xij is the i=1 j=1 quantity of implemented elements of the EIS project variant.
m1 mn ( X ) = PF ( p1 j x1 j ,..., pnj xnj ) is the j=1 j=1 indicator of reliability of operating modes implementation of the developed EIS. It used as the objective function.
We should consider the method of forming the estimation of the cost indicators of used elements. At the stage of synthesis of the structural and functional appearance variants of the EIS, the authors propose using the following formula for an indirect integral assessment of the economic efficiency of the selected components based on a serviceoriented approach: cij =
Ci Sj / Tc + We ,
Vijs / T
l=1
where Tc is the duration of the depreciation
period; We is total operating costs associated
with maintaining the operation of the element
for a given life cycle period; Vijs is the amount
of data that the implemented element must
process, transmit, and store for supporting the
(1)
functioning of the specified information
service of the EIS. Information service is the
service that the information system provides to
the BP [
For considering the duplication, triplication etc. of implemented elements we should additionally introduce the constraint mi xij 1,i N . It has the following j=1 interpretation: the maximum redundancy rate Ai of the implemented element into the projected EIS is not more than mi ; at the same time xij = 1 when the redundancy Ai is made by the element with j rate. In this situation, the changing of values goes in the following way: the probability of failure-free operation pi1 = pi , pi2 =1− (1− pi )2,..., pimi =1− (1− pi )mi ,i N the cost estimation of using ci1 = ci ,ci2 = 2ci ,...,cimi = mici ,i N; quantity of
introduced i1 = 1,i2 = 2,...,imi = mi ,i N.
It is important to mention that the reserve elements are introduced into the EIS, but they are not used during the normal operation. This makes it possible to produce the “hot-swap” of elements in the event of equipment failure, as well as to create the main, backup and duplicate control circuits, which is an accepted practice for critical infrastructure facilities.
The number of elements of the
implemented EIS should be minimized,
because the unused elements are exposed to
moral wear and tear, and working with a wide
fleet of equipment increases the complexity of
maintenance and administration. Additionally,
[
the elements we should note that excessive resources are frozen assets.
The presented constraints define the range Δ of permissible structural and functional features of the considered EIS. The problem of variants synthesis is reduced to a multi-criteria problem of choice on a discrete set of acceptable alternatives: min C( X ), minV ( X ), max ( X ). (2) X X X
In other words, it is necessary to find effective (Pareto) variants of the EIS project nd that ensure minimum financial costs, minimum number of EIS implemented elements and maximum reliability indicator of the EIS elements functioning.
For more information about the approach
based on the method of constructing a
lexicographic relationship of preference and
successive concessions, which allows to
resolve the criterion uncertainty, see [
Next (the second stage of research), we
should present models and algorithms for
synthesis integrated programs for the
functioning and modernization of the EIS. At
this stage, the disclosure of all connections
between the physical and executive levels of
the information system is pointless, because
this will lead to the excessive complication of
the model [
We should highlight that the proposed method allows to describe the connections of hierarchical system and rely on the programtarget and service-oriented approaches at the planning stage of conducting a “seamless” EIS modernization. At the same time, it is possible to explicitly consider the requirements for minimizing the total cost of ownership at a specific stage of the system's life cycle [15].
Determined at the first stage, an effective variant of the implemented elements (EIS appearance) allows to get the characteristics (the bandwidth of communication nodes, the computing power of new servers, etc.) that are necessary for synthesizing an integrated plan and schedule of the EIS functioning and modernization. The choosing among alternative options is based on the search for the extremum of the combined generalized criterion selection function.
Thus, the model of planning and scheduling of the EIS functioning and modernization has the form (3). Expressions (3) describe the logical-dynamic model of managing the EIS information services.
S v (o,v) (t) ul(ioj,v) ; x(o,v) = r ij
l=1 lij x(o,v) (t0 ) = 0; xi(jo,v) (t f ) = ai(jo,v); ij Sj m ulij i (o,v) Pi(o,v) ;l,i;
(o,v) Pj(o,v) ;l,j;ulij i=1 j=1 ul(ioj,v) (t) {0,1}; (3) ul(ioj,v) (ai(o,v) − xi(o,v) ) + zd (ai(jm,v) − xi(jm,v) ) = 0, 1 i =1 where xi(jo,v) is the variable that characterizes the current state of the service implementation operation; r (o,v) is the matrix lij time function that sets the space-time constraints associated with the provision of the service. It takes the value 1 if the operation can be performed and 0 in the opposite case; ul(ioj,v) is the control variable, which takes the value 1 if the information service uses the EIS information resource, and 0 in the opposite case; xi(jo,v) (t0 ) and xi(jo,v) (t f ) are boundary conditions at the initial and final time points, respectively; a(o,v) is the total volume of the ij operation; Pi(o,v) , Pj(o,v) are the constants which determine the ability to simultaneously use several information resources for the implementation of the service and characterize technical and technological limitations of the selected architecture and the nomenclature of elements that were defined at the first step; 1 is the set of operation numbers that characterize the state of implementation of the information service and which are directly preceding and technologically related to the current operation using the logical operations "AND"; a(m,v) is the specified volume of ij operations included into the technological cycle of information resources modernization; x(m,v) is the variable that characterizes the ij current state of the operation of upgrading the information resource.
The presented expressions (3) allow to set the inter-level restrictions of the following type: the information service cannot be submitted until the modernization of the information resource is completed see Figure 3. for the failure of the directive deadlines for providing the service; lij ( ) is a given time function that characterizes the current downtime price of the information service; The function of the form (10) describes changes in the total cost of ownership of the EIS system at the stage of modernization; cl(ioj,v1) ( ) are given non-linear time functions, which are used to set the current prices of costs associated with depreciation and maintenance of the service. The presented approach to the EIS modernization works allows to comprehensively get to the problems of the structural and functional appearance synthesis and the development of coordinated work plans. For more information about the algorithm for finding the operation and modernization of the CTS optimal program based on the Boltyansky local cut method, see [16].
Relying on the principles of the
serviceoriented approach allows the introduction of
the abstraction "information service", which
leads to a reduction in the dimension of the
solvable problems. Due to the minimization of
the number of connections between the
physical and information levels and the use of
mixed constraints in (7). There is a unique
opportunity to operate only with an active
front of work at the stage of a comprehensive
plan and schedule for EIS functioning and
modernization synthesis. We consider the
constraints that affect the current processes at
different levels of the hierarchy. Such a
formulation of the problem of program
synthesis for the modernization of the EIS
gives an opportunity to involve the
fundamental results obtained in the modern
theory of proactive control of the CTS
structural dynamics [
We should present the initial data for the design and analysis of the implemented system appearance. Table 1 shows the data on the reliability of elements of various equipment manufacturers. In column 1 there is the data for the “old” or legacy EIS elements. In columns 2-4 there is the data on the probability of failure-free operation of elements from foreign and domestic manufacturers.
The data presented in table 2 illustrates the integrated economic assessment of elements from different manufacturers (see formula (1)) for a given EIS architecture (see Fig. 1), where column 1 contains data for legacy EIS elements, and columns 2-4 contain data from different manufacturers.
A number of effective variants of the EIS project, obtained as a result of applying the above-mentioned approach, are shown in table 3. The table shows 4 different variants of “new” EIS appearance.
PC 1-6 DATABASE
SERVER Quantity
Costs Reliability 7-4
The first number indicates the number of elements. The second number indicates the manufacturer.
Further narrowing of the set of
nondominant alternatives is carried out by
attracting experts. Clipping is based on the
study of Pareto set properties and obtaining the
additional information from the
decisionmakers (the estimation of the set power, the
range of changes in the indicators values, their
inconsistency). This stage ends with the choice
of an appearance variant of the implemented
EIS [
There is an example of the connection between the BP, the level of services and the modernization of EIS information services of the enterprise warehouse subsystem (see Figure 4) information about the products inside. Before shipping, the operating personnel must scan all items and link them to the set label. Data is entered in the registry and stored at database servers. Information services support the specified BP, but not more than two of them (see Figure 4).
It is necessary to find such an acceptable control that satisfies the constraints and transforms the dynamic system from a given initial state into a given final state. If there are several control actions, then it is necessary to choose the one among them at which the generalized quality indicator takes the extreme value. In other words, it is necessary to find a valid program of functioning and modernization of the enterprise subsystems, during the implementation of which all operations involved in the corresponding cycles of EIS information resources modernization management will be fulfilled fully and timely, and the reducing of the BP quality would be minimal.
At a given interval, it is necessary to implement modernization (replacement) of 17 EIS elements (database servers, RFID tag readers (including installation of new tags), personal computers) instead of "outdated" hardware new devices of the same manufacturer are installed, but with improved characteristics. The planning step is 1 day.
The working day is 8 hours. There are days off for a given period of work. The "resources" of the modernization are the personnel of the information service of the enterprise. Depending on the qualification, each employee involved in the modernization process was assigned "performance".
Carrying out modernization works has its own technological cycle and regulations, which are determined by the “old” and “new” architecture of the EIS, as well as the nomenclature of elements selected at the first step of the research. Based on the above, we form quality indicators for all levels of the enterprise subsystem (the BP, the level of services and modernization): full completeness of operations; efficiency and cost of works.
As a dispatching solution, a combined heuristic plan developed on the basis of the "FIFO" principle was chosen. The Figure 5 shows the plan as a schedule of work for the modernization of EIS information resources.
Abbreviations are introduced: IR 1.1 is information resource No. 1.1.; Day 1 is a planning interval; the constant in the center of the rectangle indicates the amount of resources that were allocated for modernization; a blue rectangle stands for ‘operation of information resources modernization has been successfully completed’; a yellow rectangle is for ‘operation of information resources modernization violated the directive deadline; a red rectangle is for ‘failure of the modernization deadline’.
Figure 6 shows the optimal plan and schedule of EIS modernization.
The implementation of the developed approach allowed to increase in average by 515% the generalized indicator of completeness and efficiency of operations. Cost indicators in monetary terms are improved by 10-14% in average compared to the values of similar indicators calculated using traditional heuristic methods and algorithms of solving problems of planning and scheduling.
The presented approach allows to increase the validity of management decisions made at the stages of determining the composition of the hardware of “new” EIS and synthesizing programs for joint functioning and modernization of the CTS.
The proposed approach allows to note the high integration of mathematical models within a single combined planning algorithm based on the principles of a service-oriented approach. The study opens up the prospects for forming the reasonable requirements for the characteristics of the EIS hardware complex for CTS.
The paper presents one of the possible ways of analysis the influence of the selected EIS elements on the plans and schedules of information system functioning and development. It is advisable to apply at objects that are at the most modern level of development, otherwise the benefits of optimal functioning and modernization programs of information resources will be offset by organizational and technical shortcomings of the BP.
Integrated planning of the functioning and modernization of the EIS is a time-consuming process that requires the involvement of decision-makers who understand the specificity of the subject area. Thus, the further direction of research is the search for ways of considering the contradictory connections of various quality indicators of the developed plans, as well as the automation of the proposed approach. On the website [17], the reader will find information about the practical implementation of the developed models and algorithms in the framework of solving integrated planning problems.
The research described in this paper is partially supported by the Russian Foundation for Basic Research (19–08–00989, 20-0801046), state research 0073–2019–0004. [15] R. M. Yusupov, A. A. Musaev,.
Efficiency of Information Systems and Technologies: Features of Estimation. SPIIRAS Proceedings, 2 (51), (2017) pp. 5-34. https://doi.org/10.15622/sp.51.1 [16] V. N. Kalinin, B. V. Sokolov, A dynamic model and an optimal scheduling algorithm for activities with bans of interrupts. Automation and Remote Control, 48(1–2), (1987) 88–94. [17] https://litsam.ru