An EPC function diagram must begin with at least one start event (the start event may follow the process interface) and end with at least one end event (the end event may precede the process interface).
Events and functions in the course of the process must alternate. Decisions about the further course of the process are made by the functions.
The recommended number of functions in the diagram is no more than 20. If the number of functions in the diagram significantly exceeds 20, then there is a possibility that the processes at the top level are incorrectly identified and the model needs to be corrected.
Events and functions must contain exactly one incoming and one outgoing connection, reflecting the progress of the process.
The events and statements surrounding the function in the overlay diagram must be the start/outcome events and statements in the function decomposition diagram.
The diagram should not contain objects without a single connection. Each merge operator must have at least two incoming links and only one outgoing one, the branching operator must have only one incoming link and at least two outgoing ones. Operators cannot have multiple incoming and outgoing connections at the same time. If an operator has an incoming connection from the "event" element, then it must have an outgoing connection to the "function" element and vice versa. A single event must not be followed by "OR (OR)" or "XOR (Exclusive OR)" operators. Operators can merge or branch only functions or only events.
Rice. 2.62 Example of a process diagram in EPC notation
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| Rice. 2.63 Acceptable situation example 3 | Rice. 2.64 Acceptable situation example 4 |
An example of an invalid situation.
Rice. 2.65 Example of an unacceptable situation
Statistical Methods process management
Examples of the most popular methods of statistical analysis are given and a mechanism for their evaluation is proposed.
Pareto Chart Analysis
On the industrial enterprises all sorts of problems constantly arise: the appearance of marriage, equipment malfunctions, etc. In most cases, the vast majority of defects and related losses occur due to a relatively small number of reasons, with the share of material costs being about 70 - 80%. To find out which of these causes or factors are the main ones, a Pareto chart is built.
The Pareto diagram is a tool that allows you to objectively present and identify the main causes that affect the problem under study. There are two types of Pareto charts: by results of activity and by causes.
The performance chart is designed to identify the main problem and reflects the following undesirable performance outcomes:
Cost: volume of losses, costs;
· Safety: accidents, accidents;
· Terms of deliveries: failure of terms, shortage of stocks.
The Cause Pareto Chart reflects the causes of problems that arise during production:
· Performer of work: shift, team, etc.;
· Equipment: machines, aggregates, tools, etc.;
· Working methods: sequence of operations, production conditions;
· Measurements: accuracy, reproducibility, stability.
The construction of the Pareto chart consists of the following steps.
Stage 1. Determine what problems need to be investigated and how to collect data; how to classify them. Set the data collection method and period.
Step 2: Develop a data recording checklist listing the types of information collected.
Step 3. Complete the data entry sheet and calculate the totals.
Step 4. Develop a table template for data checks, providing in it a graph for the totals for each checked feature individually, the accumulated sum of the number of defects, percentages of the total, and accumulated percentages. Arrange the data in order of importance.
Table 3.1.1 Building a Pareto chart
| Defect code | Number of defects | Cumulative sum of the number of defects | Percentage of defects | Accrued interest |
| Total | - | - |
Step 5. Draw one horizontal and two vertical axes. Vertical axes: on the left axis, apply a scale with an interval from 0 to the number corresponding to the grand total; on the right axis - a scale with an interval from 0 to 100%. Divide the horizontal axis by the number of controlled features.
Rice. 3.1.1 Pareto chart
Step 6. Build a bar graph, where each type of marriage has its own rectangle.
Step 7. Draw a cumulative line.
When constructing a diagram, you should pay attention to the following points:
· The diagram is most effective if the number of factors is 7 - 10;
· When processing data, it is necessary to stratify them according to individual parameters (time of data sampling, type of products, batch of materials, operator, etc.);
· If the “other” factor is too large, the analysis of the content of this factor should be repeated;
Chart should be done systematically. Pareto for the same process, which will allow you to track the trend in the number of defects for each factor (Fig. 3.1.1).
September 22, 2010 8:30 pm"Kites, blind man's bluffs and tags
Hide and seek, balls, leapfrog, and jump ropes,
And simple, and simple, and just jump ropes,
Well, just, just, just skipping ropes!!!”
A.Vratarev
While preparing this article, I discovered an incredible fact: about the EPC notation, so simple and so popular (there are opinions that it is even more popular than BPMN), Wikipedia has articles in only 4 languages: English, German, Czech and Uzbek. Moreover, these articles are quite short. Perhaps, by the end of the article, you and I, dear reader, will understand why.
And I'll start by saying that the EPC notation was developed in the early 1990s. during the development of the ARIS methodology, as, say, its process component. The founding father of the EPC is considered to be Professor Wilhelm-August Scheer, whose name alone inspires awe in the layman (say it out loud and feel it). What can we say about the name of the faculty where this respected uncle worked: Institut für Wirtschaftsinformatik of the University Universität des Saarlandes.
The purpose of creating the EPC notation was the ability to describe processes so that the functions performed inside them have global semantics within the diagram, which means that the execution of a function on EPC diagrams is not necessarily clearly defined, but may be dependent on the state of other nodes of the diagram, sometimes very far apart. from each other.
The name of the notation stands for Event-driven Process Chain, which clearly indicates that the central element of the EPC notation diagrams are events. Events give rise to the performance of certain actions by certain participants. The completion of the execution of actions, in turn, generates another event, and so on, until the system comes to a state, the appearance of which within the process is considered the final event.
For a visual demonstration of the possibilities of notation, I will use an everyday example inspired by a recently completed vacation in warmer climes. The receptionist of a respected hotel, Ivo Petkov, receives a request from one of the guests for an urgent replacement of the bathroom amenities in the room. It is quite clear that its task is to fulfill the client's request, and in terms of EPC - to bring the system from the state "Request received from the client to change wash accessories" to the state "Client's request is satisfied".
We expose the two indicated states on the draft diagram and immediately notice how easy our diagram will be to read, because each of its elements has not only its own shape, but also its own color. So, events are red hexagons, functions are green rectangles with rounded edges, and performers are depicted as yellow ovals.
So, back to the example. Immediately after receiving a request from a client, Ivo must send a request to fulfill the client's request to the maid, which will bring the system into the "Execution request sent" state. The maid, using the stock available in the warehouse, fulfills Ivo's request. And here, for the first time, the parallelization of our process appears: if the maid understands that the necessary washing accessories (say, shower gel) are not currently in stock, then she herself, perhaps unwittingly, transfers the system to the state “Request execution is impossible”, from which it follows that Ivo will have to have not the most pleasant conversation with the client, and the state the system will come to next depends only on the client's temper and his tendency to fight. If the warehouse has all the accessories necessary for the guest, then the maid successfully fulfills the request sent to her, informs Ivo about the fulfillment, who in turn informs the client about it. And everyone lives happily ever after and dies on the same day.
This simple process was reflected in such a joyfully winking red, green and yellow diagram, as in Figure 1.
Rice. 1. EPC-diagram of the process of processing a client request in a hotel
And now, according to tradition, the advantages and disadvantages of notation.
When I first encountered EPC diagrams, as I mentioned earlier, I was very pleased with how easy they are to read: each block is highlighted in shape and color, it is very easy to see the performers, required materials, highlight the list of possible system states, the list of executed in during process functions. This is undoubtedly a huge plus: the customer will not have difficulty reading the business process diagram when implementing the EDMS, if it is presented in EPC notation. However, it is possible that such a huge number of states will confuse the customer, because in fact, because of them, the circuit grows greatly. Even in our example: some 4 functions generated as many as 5 states (not counting the initial one). Sometimes you will think: why should they all be indicated. Let's say why it is necessary after agreeing the contract CEO indicate in a separate block “Agreement agreed”, and after signing - “Agreement signed”, if the process still remains linear. Frankly, there is no need, unless you are Captain Obvious.
And sometimes it is not clear how to select the state into which the function will transfer the system. Even when preparing this simple example, I experienced certain difficulties associated with just this moment.
The advantage of EPC-diagrams is the fact that, as in IDEF0 diagrams, they can indicate the input and output data of each function, trace the logic of the movement of input and output data from block to block. In addition, unlike the same IDEF0, it became possible to parallelize the process, directing it only along one of the alternative branches (in IDEF0, if we add parallelism in execution, then all parallel functions will be executed simultaneously). The advantage also seemed to me the ability to specify the performer for each stage (read: functions).
But! In IDEF0, the executor is specified once at each level of decomposition, and arrows are drawn on its behalf to all the blocks it executes. In EPC, to calculate how many actions an executor performs, you need to run through all the action blocks and check if the executor we need is indicated on it.
This notation seemed very convenient to me from the point of view of monitoring the execution of the process: each function will certainly transfer the system to a new state, which means that after the execution of each function, the system can be checked whether the transition to the desired state has really been made. But then the question arose: is it really necessary? For example, I rarely have such a desire =)
So, in general, the EPC notation seems to me inconvenient for describing business processes: too much attention to events, too little attention to actions and, in particular, their grouping according to the artist or materials used. Yes, she is simple, yes, she is beautiful, and yes, unfortunately, that's all I can say about her, as probably many other people. =)
And articles about UML and BPMN notations are getting closer and closer.
(4.14 - rated by 21 people)
MOSCOW STATE TECHNOLOGICAL UNIVERSITY "STANKIN"
LABORATORY WORKS
ON
DISCIPLINE "TOOLS OF CALS-TECHNOLOGIES"
Moscow 2009
LAB #1
Objective: Formation of skills for developing a business process model using an EPC diagram.
Work tasks:
1. Studying the rules for constructing an EPC diagram;
2. Development of an EPC diagram of a business process in accordance with the task.
Rules for constructing an EPC diagram
Chart objects:
| An object | Description |
| Functions are elementary actions aimed at the implementation of a business process | |
| A department or a separate state unit that performs a function | |
| Position (including multiple positions) in organizational structure, performing the function | |
| Information carriers, both material form (paper documents, etc.), and electronic representation of information: files, emails, Internet resources, etc. | |
| A product or service that results from or is required to perform a business function | |
| Information flows providing process inputs and outputs | |
| Qualitative or quantitative situation (state), the achievement of which is important for the company | |
| Regulations |
Relationships of chart objects:
|
1. To build a diagram of an event-driven process, the objects specified in the "Objects" section and the relationships between them specified in the "Object Relations" section are used.
2. The diagram defines the sequence of actions and events required to complete the process. Each EPC model must begin with at least one start initiating event (state) and end with at least one resulting event (state). Events and functions in the course of the process must alternate (change each other) (Fig. 1).
Rice. 1. Functional-event sequence of the business process
- All functions must go in the correct sequence. It is necessary to consider whether they are parallel or sequential.
- Events and functions should have only one incoming and one outgoing relation showing the progress of the business process.
If there are branches, then it is necessary to use the branching operator, while showing all possible options for the flow of the process and the results of the execution of functions. The branching always starts after the function.
On the eEPC diagram, the following use cases for branch/merge rules are allowed:
1) Conditional branching of the process using the "exclusive OR" operator (when the function is executed, only one of the possible events occurs) (Fig. 2).
Rice. 2. Branching with the XOR operator
2) Conditional branching of the process using the “OR” operator (during the execution of the function, either one event occurs, or the other, or both at once) (Fig. 3).
Rice. 3. Branching with the "OR" operator
3) Conditional branching of the process using the "AND" operator (when the function is executed, both events occur) (Fig. 4).
Rice. 4. Branching with the "AND" operator
4) The function will be executed if both events have occurred (Fig.5).
Rice. 5. Connection with the "AND" operator
5) The function will be executed if either one event or the other has occurred, but not both at once (Fig.6).
Rice. 6. Connection with the XOR operator
6) The function will be executed when at least one of the events has occurred (Fig.7).
Rice. 7. Connection with the "OR" operator
- The same operators must be used at the input and output of the branch (Fig. 8).
Rice. 8. Using Operators on Entry and Exit
- The previous and subsequent processes are determined and displayed in the interfaces (Fig. 9). If there are no previous and subsequent processes within the company, then the “Process Boundaries” object (“Process Start”, “Process End”) is used.
Rice. 9. Functional-event sequence of a business process with interfaces, indicating the boundaries of the process
- All the necessary information and resources needed to perform the function, as well as the results of the function execution, are determined and displayed. It is necessary to accurately display incoming and outgoing information. For such documents as: Order, Memo, Application, etc., it is necessary to indicate their purpose. Information that is transmitted orally, as well as unstructured information on any media, is displayed with an information icon (Fig. 10).
Rice. 10. Functional-event sequence of a business process with interfaces, incoming and outgoing information
- The executor of each function is determined and displayed (Fig. 11).
Rice. 11. Functional-event sequence of a business process with interfaces, incoming and outgoing information, regulatory documents and performers
- The possibility and necessity of function decomposition is determined. If necessary, the functions are described in more detail on the EPC diagram and reference is made to it.
Abazhur Group specializes in the implementation of diverse construction projects based on EPC / EPCM contracts ... But for those who are in search and do not yet know what EPC and EPCM are, we offer a collection of materials that, we hope, will be of help to our Partners and clients when work with such relatively new instruments for domestic practice as EPC-, EPC(M)-contracts.
Structuring, conclusion and execution of EPC and EPC(M) contracts
Abazhur Group specializes in the implementation of diverse construction projects based on EPC / EPCM contracts, as well as other construction contracts with individual conditions. , applies system solutions in construction using BIM modeling, creates building projects that achieve low capital intensity.
EPC/EPCM contracts are the most common type of contracts in the construction industry.
When choosing one form or another, it is important to remember that the type of contract can lead to a significant change in the level of costs and risks that are associated with the construction of large and large structures. The level of costs is proportional to the risks assumed by the customer. With the reduction of commercial risks taken by the owner, the costs of building the facility and its management increase. In any business, this is logically confirmed by the risk-reward link.
The obligations assumed by the general contractor most often include the provision of four types of services:
- Engineering– survey work, project creation, documentation approval;
- Procurement– selection, purchase and supply of equipment and materials necessary for the performance of all works;
- The construction of the object (Construction)– construction, assembly and commissioning;
- Management of all construction processes (Construction Management).
Contract strategy in the implementation of large construction projects
Reducing the construction time is often possible due to the fact that the EPC contractor, being the only person responsible to the customer, can develop and issue a design and working documentation in parallel with the procurement of materials and equipment, as well as the implementation of construction and installation works.
for instance, the EPC contractor may not wait for the development and approval of the entire project documentation in order to start contracting equipment for a long production cycle.
The effective use of parallel design in a number of cases makes it possible to seriously reduce the overall construction time. This is especially true for some gas projects, especially associated petroleum gas processing/treatment projects, where there may be a peak in production, by which time a gas treatment plant must be built, otherwise the overall profitability of the project is seriously impaired. In such cases, the use of the EPC model of project implementation is justified, which, despite the higher cost, allows the construction to be completed in a shorter time.
Each contract strategy is a "traditional" model of managing the forces of the customer and the EPC model has its own strengths and weaknesses. For comparison, we provide tables that systematize the negative and positive aspects of each strategy.
EPC(M)-contract
The EPC(M) structure is a contractual solution that, in terms of risk sharing, lies in the middle between the multi-lot and EPC contract models. It should immediately be noted that there is no single and unambiguous understanding of what is considered an EPC (M) contract. Such an agreement can be understood, for example, as a situation where the EPCM contractor acts solely as a consultant, not entering into any subcontracts on its own behalf.
Similarly, an EPC(M) contract can be called a full cycle general contract, but in which the price is determined on the basis of an “open book” (open book) or “reimbursement” (cost + fee, reimbursable)*. The complexity of the terminology is also introduced by the fact that none of the leading international organizations (FIDIC, ICC Orgalime) has issued a proforma of the EPC(M) agreement.
* In our opinion, it is more correct to call such contracts
EPC open book and EPC reimbursable or cost plus fee respectively
EPC(M) is the English abbreviation for Engineering Procurement Construction Management. At the same time, the correct translation of this abbreviation into Russian is "Design, Supply, Construction Management". In the EPC(M) model, the word management most often refers specifically to construction in the narrow sense of the word, i.e. to perform construction and installation and other works on the site.
Subject to the previously made reservations about vagueness in terminology:
An EPCM contract is most often understood as such a structure when the EPC(M) contractor, on its own or by a subsidiary company, carries out design, independently contracts equipment and materials, but in terms of construction and installation works, it only manages, i.e. does not hire construction and installation contractors on its own behalf, but only on behalf of the customer manages the contractors hired by the customer.
The fundamental difference between the EPC(M) contract and the EPC contract is that the EPC contract is an agreement on the "acceptance of responsibility and risks"
By entering into an EPC contract, the customer largely shifts the risks and responsibility to the EPC contractor which must provide this responsibility with liquid property. The EPC(M) contract is a professional services agreement the customer "buys" competencies, the responsibility of the EPC(M)-contractor for the timing and budget of the project is absent or negligible in comparison with the cost of the project and, therefore, is of an exclusively stimulating nature.
There are various options for structuring the price in the EPC(M) contract, but it is never firm. Often the price is a combination of time rates (for those functions that the EPCM contractor performs personally - design, procurement management, construction management) and the "open book" principle.
This principle means that
- subcontracting is carried out in a transparent way for the customer and with the participation of his representatives;
- the contractor discloses the structure of its own overheads, as well as the amount of the expected profit, and such overheads / profits are either fixed at a certain amount or added as a percentage surcharge to the cost of each supply contract.
As already noted, the responsibility of the EPC(M) contractor is very limited and more like the responsibility of a consulting engineer (who is only responsible for dishonest or incompetent provision of own services) than the responsibility of the general contractor.
At the same time, quite often in EPC(M) contracts there are incentive mechanisms for the contractor using the principles bonus/malus (so-called gain sharing / pain sharing).
for instance, the contract may provide that when the facility is put into operation at an earlier date, the contractor receives additional remuneration; in case of delay, the contractor, on the contrary, loses part of the profit.
Similarly, incentives can be built in relation to the total: the parties can set a certain target budget, and if, by effectively managing the construction, the contractor achieves savings, then such savings are divided between the parties in an agreed proportion. However, the EPC(M) contractor, when agreeing on a bonus/malus, is usually not ready to risk all the reward and therefore this mechanism does not give the customer complete comfort in terms of the cost and construction time, but is only aimed at creating a material interest in the contractor in successful implementation project.
One of the advantages of the EPCM contract compared to the EPC model is the important fact that the tender for the selection of the EPCM contractor can be prepared and conducted much faster than the tender for the award of the EPC lumpsum contract. The fact is that in the first case, the customer is required to have a lower level of certainty regarding the scope of work, delivery boundaries and risks; and the contractor only needs to prepare a quotation for time rates, overheads and own profits - he is not required to prepare a firm quotation for the total cost of the project.
When tendering according to the EPC lumpsum model, on the contrary, the customer needs to prepare detailed technical task and requirements (with an insufficient level of development, contractors may either refuse to submit proposals with a fixed price at all or estimate the risks in a very large amount); likewise, the contractor needs an order of magnitude more time to prepare a proposal with a fixed price that takes into account all the risks.
Modern methods construction, high quality materials and technologies, building control and general contractor functions, industrial and commercial buildings, installation of prefabricated structures. Construction of objects of any complexity!
Terms:
EPC Contractor- this is the one that performs the bulk of the work of the investment project for a fixed price and assumes all the risks of its implementation from the moment of design and until the transfer of the finished object to the customer (including the fulfillment of warranty obligations), for which he is financially responsible to the Customer.
It is used, as a rule, in those projects where it can estimate the amount of its expenses, as well as the degree of risks, with a sufficient degree of accuracy.
The EPC contract involves that the EPC contractor performs the bulk of the work on its own, therefore no special remuneration for organizing and managing the work of involved lower-level counterparties.
EPCM contractor may enter into contracts with subcontractors on its own behalf or manage contracts concluded by the customer with specific contractors.
The EPCM contract provides and the total cost of the project, taking into account the remuneration of the EPCM contractor, and a fixed term for putting the facility into operation, achieving the main technical parameters of the facility. The EPCM method (approach) allows you to manage the project, and not specific works. Specific work is carried out by professionals. The task of the EPCM is to assess the required properties (capabilities, professionalism, resources, etc.) of the selected contractors/suppliers, to correctly distribute work and areas of responsibility between them. Further - to coordinate their actions, resolve controversial issues, plan general scheme project, change plans in case of critical changes with minimal consequences, and then with all the stops.
The world practice of implementing investment projects highlights EPC and EPCM contracts as the most promising strategies for the implementation of complex industrial projects, which account for about 80% of projects being implemented.
For more details, read the publication prepared.
If you have any questions or comments, you can - all of them will be gratefully considered.
The EPC method was developed by August-Wilhelm Scheer as part of the work on the creation of the ARIS (Architecture of Integrated Information Systems) methodology. information systems) in the early 1990s.
A process (function) diagram in EPC notation is an ordered combination of events and functions. For each function, initial and final events, participants, performers, material and information flows accompanying it can be determined, and decomposition into lower levels can be carried out.
1. An EPC process diagram must begin with at least one start event (the start event may follow the process interface) and end with at least one end event (the end event may precede the process interface).
2. Events and functions in the course of the process must alternate.
3. The recommended number of functions in the diagram is no more than 20. If the number of functions in the diagram significantly exceeds 20, then there is a possibility that the processes at the top level are incorrectly identified and the model needs to be corrected.
4. Events and functions must contain strictly one incoming and one outgoing connection (control flow), reflecting the progress of the process.
5. The diagram should not contain elements without a single connection. An exception may be the “goal” element of the entire process (diagram).
6. The events and logical operators surrounding the function in the overlying (parent) diagram must be the initial/resulting events and operators in the function decomposition diagram.
7. Each merge operator must have at least two incoming links and only one outgoing one, a branching operator - only one incoming link and at least two outgoing ones. Operators cannot have multiple incoming and outgoing connections at the same time.
8. Logical operators can combine or branch only functions or only events. It is not possible to merge/branch a function and an event at the same time.
9. The logical operator branching the branches and the operator combining these branches must match. The situation is also allowed when the branch operator is “AND”, the union operator is “OR”.
Examples of acceptable and unacceptable situations are shown in the following figure.
a) acceptable situations
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b) unacceptable situations
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Rice. 8.7. Examples of Valid and Invalid Use of Logical Operators
10. The number of line crossings should be minimized. It is assumed that the intersecting lines have no logical connection with each other. In other words, the flows at the intersections do not change their direction.
8.7. An example of building an EPC diagram
The following figure shows an example of an EPC diagram of the Pre-Project Survey process from the training materials for the Business Studio software product.
Rice. 8.8. EPC Diagram for the Pre-Project Survey Process
One of the distinguishing features of the notation used in Business Studio is the use of a generalized artist symbol ("Subject"). Despite displaying it as an organizational unit, it can also be understood as a position or person.
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