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Business Intelligence. INVENTORY CASE STUDY. Introduction. Optimized inventory levels in stores can have a major impact on chain profitability: minimize out-of-stocks reduce overall inventory carrying costs. Value chain example. We will examine this in our Analysis Services project.
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Business Intelligence INVENTORY CASE STUDY
Introduction • Optimized inventory levels in stores can have a major impact on chain profitability: • minimize out-of-stocks • reduce overall inventory carrying costs
Value chain example We will examine this in our Analysis Services project Value chain • What is the primary objective of most analytic decision support systems ? • monitor the performance results of key business processes • each business process produces unique metrics at unique time intervals with unique granularity and dimensionality • each process typically spawns one or more fact tables • value chain provides high-level insight into the overall enterprisedata warehouse
Some Common Questions related to Inventory • How did the inventory level changed per product, per warehouse over time? • How is the profitability of products in our inventory? • How many times have we placed a product into an inventory bin on the same day we picked the product from the same bin at a different time? • How many separate shipments did we receive from a given vendor, and when did we get them? • On which products have we had more than one round of inspection failures that caused return of the product to the vendor? • … etc. BI helps answering these questions
BI Inventory Models • The three main models discussed: • Inventory Periodic Snapshot • Inventory Transactions • Inventory Accumulating Snapshot They are complementary models, and provide different information about the Inventory
Periodic SnapshotThe most common inventory scheme Example of Retail Store Chain Inventory: • The assumed atomic level of detail is: • Inventory per product • Per day • Per Store Basic dimensions: Product Day Store Fact: Inventory
Simple Inventory Periodic Snapshot Usage: Provide information about inventory levels: Daily Inventory level Average Inventory level over a time period • Problems: • Inventory levels are semi-additive (i.e. NOT additive through each dimension) • Through the Date dimension the quantity on hand is NOT additive • Historical Inventory data using daily granularity results in unreasonably huge amount of data over time • Suggestion to define distinct atomic time period for short and long term measures
Enhanced Inventory Periodic Snapshot Velocity of inventory movement becomes measurable Key concepts: • Number of Turns • Number of days’ supply • Growth Margin Return on Inventory (GMROI) Extra recorded facts
Enhanced Inventory Periodic Snapshot Extra recorded facts
Enhanced Inventory Periodic Snapshot GMROI - Growth Margin Return on Inventory • GMROI is a standard metric used by inventory analysts to judge a company’s quality of investment in its inventory. • We do not store GMROI in the fact table because it is not additive!!!
Inventory Transactions Record every transaction that affects inventory:
Inventory Transactions • Use: Measure the frequency and timing of specific transaction types • Example: • How many times have we placed a product into an inventory bin on the same day we picked the product from the same bin at a different time? • How many separate shipments did we receive from a given vendor, and when did we get them? • On which products have we had more than one round of inspection failures that caused return of the product to the vendor?
Inventory Accumulating Snapshot In progress!!! • In a single fact table row we track the disposition of the product shipment until it has left the warehouse • only possible if we can reliably distinguish products delivered in one shipment from those delivered at a later time • also appropriate if we are tracking disposition at very detailed levels, such as by product serial number or lot number
Value Chain Integration • Integrating business processes together benefits: • Intelligence aspects: • Better understand customer relationships from an end-to-end perspective • Observe information across business processes • Technological aspects: • Reusability • Less resources used • Question: How do we properly integrate all business processes in the enterprise? • Answer: Data Warehouse Architecture
Data Warehouse Bus Architecture • Bus: • “Common structure to which everything can and is connected” • Data Warehouse Bus Architecture: • Defining a standard warehouse architecture (bus interface) to which different data marts can connect. • Standardizes dimensions and facts that have uniform interpretation across the enterprise. • Architectural framework for the overall design and separate data marts following the framework.
Data Warehouse Architecture Kimball vs. Inmon • Bill Inmon and Ralph Kimball – the co-founders of the data warehouse concept and their views on data warehouse architecture • Dependent Data Mart Structure (Inmon) • Let everyone build what and when they want and we will integrate it if we need it. • Each data mart gets information from the operational data base and then data is loaded in the data warehouse • Data Warehouse Bus Structure (Kimball) • Design everything then build. • The data warehouse is responsible for loading data in the data marts from the operational database.
Bus Matrix • The tool we use to document the Data Warehouse Bus Architecture • A part technical, part management, part communication tool • Business processes as ROWS • Common dimensions as Columns
Bus Matrix (cont.) • Rows : • Business processes • A business process translates into a First-Level Data Mart • Each Data Mart spanning over multiple business processes translates into a Consolidated Data Mart (E.G. Profitability) • Columns: • Common Dimension used across the enterprise • Consequences of improper or non-existent bus matrix: • Isolated data marts blocking the coherent warehouse environment, narrowing down the scope of information to be viewed. • Expansion of the data warehouse is nearly impossible
Conformed Dimensions • What are conformed dimensions: • The cornerstone of the Bus Architecture • A single, coherent view of data across the enterprise that can be reused across different Data Marts. • Conformed dimensions have: • Consistent dimension keys • Consistent attribute values • Consistent naming, attribute definitions.
Conformed dimensions (cont.) • Some characteristics of conformed dimensions • Each conformed dimension has the same meaning in each Data Mart • They are defined at the most granular level possible
Conformed dimensions (cont.) • Some considerations when defining conformed dimensions • Rolled-up dimensions • Rolled-up dimensions – having higher level of granularity • Rolled-up dimensions conform to the base-level atomic dimension if they are a strict subset of that dimension
Conformed dimensions (cont.) - Considerations (cont.) • Dimension subsetting • Two dimensions with same level of detail but representing different subsets of rows or columns • Rolled-up dimensions are another example of dimension subsetting • Advised Solution – dimension authority • Has responsibility for defining, maintaining and publishing dimensions and their subsets to all Data Marts
Conformed Facts • Conformed facts are: • Facts used living in more that one data mart. • Same rules and characteristics apply in designing and implementing them as with conformed dimensions • Few more considerations are: • Units of measure for the fact • Identical labeling • Underlying definitions and equations