ERP vs. CRM and SCM

CRM (Customer Relationship Management) and SCM (Supply Chain Management) are two other categories of enterprise software that are widely implemented in corporations and non-profit organizations.

CRM (Customer Relationship Management)

Customer relationship management (CRM) is a term that refers to practices, strategies and technologies that companies use to manage and analyze customer interactions and data throughout the customer lifecycle.

·         Marketing

·         Sales

·         Feed Back

·         Support

SCM (Supply Chain Management)

Supply chain management (SCM) is the management of the flow of goods and services. It includes the movement and storage of raw materials, work-in-process inventory, and finished goods from point of origin to point of consumption.

·         Raw material

·         Components

·         Manufacturer

·         Retailer

·         Consumer

ERP vs. CRM and SCM

The primary goal of ERP is to improve and streamline internal business processes, CRM attempts to enhance the relationship with customers and SCM aims to facilitate the collaboration between the organization, its suppliers, the manufacturers, the distributors and the partners.

Enterprise resource planning (ERP)

Enterprise resource planning (ERP):

                 Enterprise resource planning (ERP) is a category of business-management software typically a suite of integrated applications—that an organization can use to collect, store, manage and interpret data from many business activities, including:

1. product planning, cost
2. manufacturing or service delivery
3. marketing and sales
4. inventory management
5. shipping and payment

               ERP provides an integrated view of core business processes, often in real-time, using common databases maintained by a database management system. ERP systems track business resources—cash, raw materials, production capacity and the status of business commitments: orders, purchase orders, and payroll. The applications that make up the system share data across various departments (manufacturing, purchasing, sales, accounting, etc.) that provide the data. ERP facilitates information flow between all business functions, and manages connections to outside stakeholders.

Evolution of ERP

               ERP (Enterprise Resource Planning) is the evolution of Manufacturing Requirements Planning (MRP) II. From business perspective, ERP has expanded from coordination of manufacturing processes to the integration of enterprise-wide backend processes. From technological aspect, ERP has evolved from legacy implementation to more flexible tiered client-server architecture. The following table summarizes the evolution of ERP from 1960s to 1990s.

Timeline	System	Description
1960s	Inventory Management & Control	Inventory Management and control Is the combination of Information technology and business processes of Maintaining the appropriate level of stock in a warehouse. The activities of inventory management include identifying Inventory requirements ,setting targets, providing Replenishment techniques and options ,monitoring item usages, reconciling the inventory balances, and  reporting inventory status.
1970s	Material Requirement Planning (MRP)	Materials Requirement Planning(MRP) utilizes software Applications for scheduling production processes.MRP Generates schedules for the operations and raw material purchases based on the production requirements of finished goods, the structure of the production system, the current Inventories levels and the lot sizing procedure for each operation.
1980s	Manufacturing resource planning (MRP II)	Manufacturing Requirements Planning or MRP utilizes Software applications for coordinating manufacturing processes, from product planning, parts purchasing, inventory control to product distribution.
1990s	Enterprise Resource Planning (ERP)	Enterprise Resource Planning or ERP uses multi-module application software for improving the performance of the Internal business processes. ERP system soften integrate Business activities across functional departments, from Product planning, parts purchasing, inventory control, Product distribution, fulfillment, to order tracking.ERP Software systems may include application modules for Supporting marketing, finance, accounting and human resources.

Modelling with ER diagram

Entity-relationship diagram

                  An entity relationship model, also called an entity-relationship (ER) diagram, is a graphical representation of entities and their relationships to each other, typically used in computing in regard to the organization of data within databases or information systems.

Entity

                   Entities are represented by means of rectangles. Rectangles are named with the entity set they represent.

Entity

Weak entity

                Weak entity is an entity that cannot be uniquely identified by its attributes alone. It could be represented by double bordered rectangle

Attributes

                Attributes are the properties of entities. Attributes are represented by means of ellipses.

Multi valued attributes

               Multi-value attributes may contain more than one value. For example, a person can have more than one phone number, email_address, etc.

Derived attributes:

           Derived attributes are the attributes that do not exist in the physical database, but their values are derived from other attributes present in the database. 

           

               For example, average_salary in a department should not be saved directly in the database, instead it can be derived. For another example, age can be derived from data_of_birth.

Key Attribute

             

Key is an attribute or collection of attributes that uniquely identifies an entity among entity set.

Examples for entity and attribute

Employee Table

Example 2 : Summary

Relationship:

                   Relationships are represented by diamond-shaped box. Name of the relationship is written inside the diamond-box.

Relationship Symbol

Weak relationship

                    A weak relationship type is represented by a double diamond. 

Weak Relationship

The following diagram is the ER-diagram of the Company Database with the specifications

Network data model

Network data model

1. A network database model is a database model that allows multiple records to be linked to the same owner file. 
2. The model can be seen as an upside down tree where the branches are the member information linked to the owner.

   

   Network Model : Tree of Record View

   
   

Advantages of a Network Database Model

1. Because it has the many-many relationship, network database model can easily be accessed in any table record in the database
2. For more complex data, it is easier to use because of the multiple relationship founded among its data
3. Easier to navigate and search for information because of its flexibility

Disadvantage of a Network Database Model

1. Difficult for first time users
2. Difficulties with alterations of the database because when information entered can alter the entire database

Relational Data Model.

Relational Data Model  

Relational model stores the data in the form of table. It consists of three major components.

1. The set of relations and set of domains that defines the way data can be represented.
2. Integrity rules that defines the procedure to protect the data.
3. The operations that can be performed on the table.
   

Advantages:

1. Ease of use: 
• Any information as tables consisting of rows and columns is much easier to understand .
2. Flexibility: 
• Different tables from which information has to be linked and extracted can be easily. 
3. Security: 
• Security control and authorization can also be implemented more easily by moving sensitive attributes in a given table into a separate relation with its own authorization controls.
4. Data Independence: 
• Data independence is achieved more easily with normalization structure used in a relational database than in the more complicated tree or network structure.
5. Data Manipulation Language: 
• The possibility of responding to query by means of a language based on relational algebra and relational calculus 
• Example: SQL is easy in the relational database approach.

Disadvantages :

1. Performance: 
• A major constraint and therefore disadvantage in the use of relational database system is machine performance. 
• If the number of tables between which relationships to be established are large and the tables themselves effect the performance in responding to the sql queries.
2. Physical Storage Consumption:
• With an interactive system, for example an operation like join would depend upon the physical storage also. It is, therefore common in relational databases to tune the databases and in such a case the physical data layout would be chosen so as to give good performance in the most frequently run operations. 
• Therefore would naturally result in the fact that the lays frequently run operations would tend to become even more shared.
3. Slow extraction of meaning from data:  
• if the data is naturally organized in a hierarchical manner and stored as such, the hierarchical approach may give quick meaning for that data.

Hierarchical Data Model

Hierarchical Data Model:

1. A hierarchical database model is a data model in which the data is organized into a tree-like structure. 
2. The data is stored as records which are connected to one another through links. 
3. A record is a collection of fields, with each field containing only one value. 

Hierarchy is based on Parent-Child Relationship

1. Parent-Child Relationship Type is basically 1:N relationship 
2. The schema for a hierarchy has a single root 
3. To represent M:N relationship in a hierarchical structure, we must allow duplication of child record instances.

Example For Hierarchical Data Model

Advantages:

1. The model allows easy addition and deletion of new information.  
2. Data at the top of the Hierarchy is very fast to access.   
3. The model relates very well to natural hierarchies such as assembly plants and employee organization in corporations.  
4. It relates well to anything that works through a one to many relationship. 

Disadvantages:

1. It requires data to be repetitively stored in many different entities.  
2. The database can be very slow when searching for information on the lower entities.  
3. Searching for data requires the DBMS to run through the entire model from top to bottom until the required information is found, making queries very slow.  
4. Can only model one to many relationships, many to many relationships are not supported.  

Logical Data Model

Logical Data Model

            In data architecture, a logical data model (LDM) is a type of data model showing a detailed representation of an organization's data,

(Enough notes for "logic data model" is provide in data model page)

Three models (for handling record-based data) are:

Logical data model is classified into three models. They are

1. Hierarchical data model
2. Network data model
3. Relational data model

Details in separate blog