1

Course overview grouped bySystem integration software types:

1. Homogeneous ERP systems integrated by using a common database.

2. Heterogeneous ERP systems from different suppliers may be integrated by using relaxed ACID properties.

3. Workflows and Relaxed transaction can send subtransactions to other systems and they may use a common (distributed) database.

4. Data warehouses integrate distributed data by sending data to a common data warehouse database by using ETL (Extract, Transform, and Load) of data from the operative systems.

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Work flow example with insurance claims.

What are the differences between Work flow diagrams and Flow chart diagrams?

3

Petri Net is an attempt to standardize Work Flows:

• Transition = Task. • Token = Case with a transaction

illustrated as a black dot in a place.• Place = Queue for cases/transactions before a transition.

4

Terminology of WorkFlow Management Coalition

• Task = Atomic logic activity in a process.

• Case = Transaction in a process.

• Place = Queue for cases/transactions before a transition.

• Process = A set of tasks and a set of conditions that determine the order of the tasks.

Workflow for making mobile control of supplier deliveries.

Delivery larger than ordered

Delivery matches an Orderline

Delivery less than ordered

Delivery is not ordered

Select a con-trol action

Product deliveries

Orderlines are replicated to the mobile controllers

New Supplier

orders.

Orderlines

Reduced product delivery

ANDJOIN

Update the local stock

Replicate the mobile registrations to the central ERP system

Error reports

Accepted product deliveries

Accepted product deliveries

End of workflow

ANDSPLIT

ANDSPLIT

Reduced orderline

InputInput is supplier orders or deliveries.

What is the most important part of the workflow from a system integration point of view?

Workflow for making mobile control of supplier deliveries.

Delivery larger than ordered

Delivery matches an Orderline

Delivery less than ordered

Delivery is not ordered

Select a con-trol action

Product deliveries

Orderlines are replicated to the mobile controllers

New Supplier

orders.

Orderlines

Reduced product delivery

ANDJOIN

Update the local stock

Replicate the mobile registrations to the central ERP system

Error reports

Accepted product deliveries

Accepted product deliveries

End of workflow

ANDSPLIT

ANDSPLIT

Reduced orderline

InputInput is supplier orders or deliveries.

How would you implement the database of the workflow?

A:

Workflow nodes

Places Activities

Colored tokens

Branches from one workflow node to another

from

to

Integrated E-commerce workflows:

1. Design the workflow between an e-commerce system and an ERP system that manage the stocks of products?

2. Is the possible to use the ERP system of the suppliers if a product is out of stock?

Customers Orders Products Orderlines

Product-stocks Locations

Example: Petri net Work flowfor global E-commerce transactions where the stocks are in the locations of the different suppliers.

1. Put products in the basket

Start

Timer

2. Confirm order-lines and update stocks in servers

4. Receive products from suppliers and update QUANTITY received

6. Send the rest of the products to the customer

End

3.Suppliers send products

Non confirmed order

Products

All products are received

5. Send the received products to the customer

Suborders

Canseled order

Stock rejected order

Confirmed order

OR split

Sub- Petri net of activity 2

2.1 try to confirm thenext order-line

Order-line

An-swer

Nonconfirmedorder

2.2 Supplier's servertry to confirm

order-line

More order-lines

2.3 Update Order with supplieranswer for each order-line

All answers received

Order-line

Order

Order

2.4 Send Order with confirmanswers to the Customer. If theOrder was confirmed The Timeris set and confirming Sub-ordersare send to the involvedsuppliers.

Timer Sub-orders

Confirmed Order

Stockrejectedorder

When are the suborders committed globally in the location of the suppliers?

AND split

OR split

AND join

Exercise

The figure illustrates an ER-diagram of a car rental company like Hertz or Avis.

Design a workflow for the car rental company including reservation, car pic up, car return, and car return service.

Customers

Car types

Reservations

Orders

Branch offices

Cars

GaragesGarage services

Pick up

Contracts

Car return

Patient records

TreatmentsDiagnoses/diseases

Patient admits Sympthoms

Doctors

Ordinations

Ordination lines

Patient discharges

...

Entities of conceptual

objects

Entities of physical objects

...Patient admit types

Patient record subtypes

Figure 1. Generalized ER diagram of a local hospital database

Medical tests

Sympthom types

Disease types

Treatment types

Patient discharges

types

Medicin types

Medicin productsMedicin

companies

Patients_____ Patient IDNameAddress

Exercise: Design a workflow for producing healthy patients.

ER-diagram for a hospital.

Opgave 1.30

Beskriv databasen for et transportfirma og dets underleverandører med et integreret logistikstyringssystem, hvor pakker kan indsættes i collies, som herefter kan indsættes i containers, der kan transporteres af firmaet selv eller andre operatører/underleverandører. Transportruternes enkelte dele kaldes ”legs”. Det er vigtigt for transportfirmaet altid at vide, hvor en pakke er også selv om der er opstået fejl, hvor f. eks. en pakke, collie eller container er blevet beskadiget og derefter genpakket. Det er også vigtigt altid at kunne vælge den optimale transportmulighed, som kan afhænge af både transporttid og pris. Beskriv herefter et workflow for det integrerede transportsystem.

Hertil 1.3.2013

Concept definitions used in logistics:

Pallet = wooden skeleton where packages may be stored in such a way that they all can be moved by a truck.

Collie = alle the packages that are stored on a pallet(palle).

Leg = Route or subroute where the transportation does not have stops

ER-diagram of a logistics management system

Transport Orders Customers

Transport medias like ships, airplanes, and trucks.

Physical containers

Scheduled routes and legs

Orderlines

Packages, Collies and Containers

Locations

Route-leg hierarchy

Package- Collie hierarchy

Routes and legs

from

to

Damagerelationship

from to

Container-routesrelationships of order 3

Transport operator

Describe the local databases in the central location of the transport company, the locations of the integrated transport suppliers, and the mobile locations of the Transport medias. Design a workflow with focus on the integration of the local database locations.

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The ACID properties are implemented by a DBMS (DataBase Management System).Relaxed ACID properties are implemented by the application programs.

• Atomicity

• Concistency

• Isolation

• Durability

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Evaluation criteria

Distribution architectures

Synchronous distributed database management system (DDBMS)

Central database with distributed clients

Multidatabases with flexible transactions.(Relaxed ACID properties)

Hot backup possibility

n-safe and mirroring Only mirroring is possible

0- safe, 1 safe and mirroring

Read performance/capacity

Best Worst Average

Write performance Worst Average Best

Blocking possibility Yes No no

Ease of failure recovery

Worst (The systems are very complex)

Best Best

Disaster recovery Best Worst Average

The probability of lost data[1]

Best.pn

Worstp

Average

Transaction logging Not supported Not supported Recommended

Availability[2] 1-qn 1-q 1-qn

Atomicity Best Best Best

Consistency Best Best Worst

Isolation Best Best Worst

Durability Best Best Best

Develop-ment costs Best Best Worst

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Evaluation of distribution architectures 1.Evaluation criteria

Synchronous distributed database management system (DDBMS)

Central database with distributed clients

Multidatabases with flexible transactions.

Hot backup possibility

n-safe and mirroring Only mirroring is possible

0- safe, 1 safe and mirroring

Read per-formance/

capacity

Best Worst Average

Write per-formance

Worst Average Best

Blocking possibility

Yes No No

Ease of failure recovery

Worst (The systems are very complex)

Best Best

Ease of disaster recovery

Best Worst Average

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Evaluation of distribution architectures 2.Evaluation criteria

Synchronous distributed database management system (DDBMS)

Central database with distributed clients

Multidatabases with flexible transactions.

The probability of lost data

Best

pn

Worst p Average

Logging of the update transaction

Not supported Not supported Recommended

Availability 1-qn 1-q 1-qn

Atomicity Best Best Best

Consistency Best Best Worst

Isolation Best Best Worst

Durability Best Best Best

Develop-ment costs

Best Best Worst

End of session

Thank you !!!Thank you !!!

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Database recovery:

Transaction types

Time

Time offailure

Check-pointtime

Transaction 1

Transaction 2

Transaction 3

Transaction 4

Transaction 5

Exersice.A DB logfile stores before images and after images of all dataabase updates. The logfile also stores transaction starts and commitments. Periodically the checkpoint records are logged with the IDs of all non committed transactions.

How is it possible to recover transaction types 1 to 5 after a transaction failure and a CPU failure respectively?

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Two Phase Commit (2PC) and Two Phase Locking (2PL)

Time

Transactionstart

Transactioncommit

Exercise.Describe the basic principles for the Two Phase Commit (2PC) recovery protocol and the Two Phase Locking (2PL) protocol for concurrency control.

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Exercise:

Describe exactly when a transaction is committed.

What is the difference between failure and disaster recovery?

Is the durability property always trustworthy?

Is it possible to run batch programs that lock many thousends records concurrent with on line updates that only locks a few records?

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ACID kravene til transaktionsafvikling:

• Atomicity = udelelighed.

• Concistency = konsistensen skal bevares

• Isolation = en transaktions opdateringer må ikke ses af andre før de er committede.

• Durability = Holdbarhed dvs. committede opdateringer skal kunne retableres.

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Full ACID løsninger. Relaxed ACID løsning.