Big Data

Dynamic Duo of Analytic Power: Business Intelligence Analyst PLUS Data Scientist

Bill Schmarzo By Bill Schmarzo CTO, Dell EMC Services (aka “Dean of Big Data”) November 19, 2014
big data analytic

Figure 1: BI Analyst vs. Data Scientist Characteristics

I recently had a client ask me to explain to his management team the difference between a Business Intelligence (BI) Analyst and a Data Scientist.  I frequently hear this question, and typically resort to showing Figure 1 (BI Analyst vs. Data Scientist Characteristics chart, which shows the different attitudinal approaches for each) and Figure 2 (Business Intelligence vs. Data Science, which shows the different types of questions that each tries to address) in response to this question.

Figure 2: Business Intelligence vs. Data Science

Figure 2: Business Intelligence vs. Data Science

But these slides lack the context required to satisfactorily answer the question – I’m never sure the audience really understands the inherent differences between what a BI analyst does and what a data scientist does.  The key is to understand the differences between the BI analyst’s and data scientist’s goals, tools, techniques and approaches.  Here’s the explanation.

The Business Intelligence (BI) Analyst Engagement Process

Figure 3 outlines the high-level analytic process that a typical BI Analyst uses when engaging with the business users.

Figure 3:  Business Intelligence Engagement Process

Figure 3:  Business Intelligence Engagement Process

Step 1:  Build the Data Model.  The process starts by building the underlying data model.  Whether you use a data warehouse or data mart or hub-and-spoke approach, or whether you use a star schema, snowflake schema, or third normal form schema, the BI Analyst must go through a formal requirements gathering process with the business users to identify all (or at least the vast majority of) the questions that the business users want to answer.  In this requirements gathering process, the BI analyst must identify the first and second level questions the business users want to address in order to build a robust and scalable data warehouse. For example:

  • 1st level question:  How many patients did we treat last month?
    2nd level question:  How did that compare to the previous month?
    2nd level question:  What were the major DRG types treated?
  • 1st level question:  How many patients came through ER last night?
    2nd level question:  How did that compare to the previous night?
    2nd level question:  What were the top admission reasons?
  • 1st level question: What percentage of beds was used at Hospital X last week?
    2nd level question:  What is the trend of bed utilization over the past year?
    2nd level question:  What departments had the largest increase in bed      utilization?

The BI Analyst then works closely with the data warehouse team to define and build the underlying data models that supports the questions being asked.

Note:  the data warehouse is a “schema-on-load” approach because the data schema must be defined and built prior to loading data into the data warehouse.  Without an underlying data model, the BI tools will not work.

Step 2:  Define the Report.  Once the analytic requirements have been transcribed into a data model, then step 2 of the process is where the BI Analyst uses a Business Intelligence (BI) product – SAP Business Objects, MicroStrategy, Cognos, Qlikview, Pentaho, etc. – to create the SQL-based query for the desired questions (see Figure 4).

Figure 4:  Business Intelligence (BI) Tools

Figure 4:  Business Intelligence (BI) Tools

The BI Analyst will use the BI tool’s graphical user interface (GUI) to create the SQL query by selecting the measures and dimensions; selecting page, column and page descriptors; specifying constraints, subtotals and totals, creating special calculations (mean, moving average, rank, share of) and selecting sort criteria. The BI GUI hides much of the complexity of creating the SQL

Step 3: Generate SQL Commands.  Once the BI Analyst or the business user has defined the desired report or query request, the BI tool then creates the SQL commands.  In some cases, the BI Analyst will modify the SQL commands generated by the BI tool to include unique SQL commands that may not be supported by the BI tool.

Step 4:  Create Report.  In step 4, the BI tool issues the SQL commands against the data warehouse and creates the corresponding report or dashboard widget.  This is a highly iterative process, where the Business Analyst will tweak the SQL (either using the GUI or hand-coding the SQL statement) to fine-tune the SQL request.  The BI Analyst can also specify graphical rendering options (bar charts, line charts, pie charts) until they get the exact report and/or graphic that they want (see Figure 5).

Figure 5:  Typical BI Tool Graphic Options

Figure 5:  Typical BI Tool Graphic Options

By the way, this is a good example of the power of schema-on-load.  This traditional schema-on-load approach removes much of the underlying data complexity from the business users who can then use the GUI BI tools to more easily interact and explore the data (think self-service BI).

In summary, the BI approach leans heavily on the pre-built data warehouse (schema-on-load), which enables users to quickly, and easily ask further questions – as long as the data that they need is already in the data warehouse.  If the data is not in the data warehouse, then adding data to an existing warehouse (and creating all the supporting ETL processes) can take months to make happen.

The Data Scientist Engagement Process

Figure 6 lays out the Data Scientist engagement process.

Data Scientist Engagement Process

Data Scientist Engagement Process

Step 1:  Define Hypothesis To Test.  Step 1 of the Data Scientist process starts with the Data Scientist identifying the prediction or hypothesis that they want to test.  Again, this is a result of collaborating with the business users to understand the key sources of business differentiation (e.g., how the organization delivers value) and then brainstorming data and variables that might yield better predictors of performance. This is where a Vision Workshop process can add considerable value in driving the collaboration between the business users and the data scientists to identify data sources that may help improve predictive value (see Figure 7).

Figure 7:  Vision Workshop Data Assessment Matrix

Figure 7:  Vision Workshop Data Assessment Matrix

Step 2:  Gather Data.  Step 2 of the Data Science process is where the data scientist gathers relevant and/or interesting data from a multitude of sources – ideally both internal and external to the organization.  The data lake is a great approach for this process, as the data scientist can grab any data they want, test it, ascertain its value given the hypothesis or prediction, and then decide whether to include that data in the predictive model or throw it away.  #FailFast #FailQuietly

Step 3:  Build Data Model.  Step 3 is where the data scientist defines and builds the schema necessary to address the hypothesis being tested.  The data scientist can’t define the schema until they know the hypothesis that they are testing AND know what data sources they are going to be using to build their analytic models.

Note:  this “schema on query” process is notably different than the traditional data warehouse “schema on load” process.  The data scientist doesn’t spend months integrating all the different data sources together into a formal data model first.  Instead, the data scientist will define the schema as needed based upon the data that is being used in the analysis.  The data scientist will likely iterate through several different versions of the schema until finding a schema (and analytic model) that sufficiently answers the hypothesis being tested.

Step 4:  Explore The Data.  Step 4 of the Data Science process leverages the outstanding data visualization tools to uncover correlations and outliers of interest in the data.  Data visualization tools like Tableau, Spotfire, Domo and DataRPM[1] are great data scientist tools for exploring the data and identifying variables that they might want to test (see Figure 8).

Step 5: Build and Refine Analytic Models

Figure 8:  Sample Data Visualization Tools

Figure 8:  Sample Data Visualization Tools

Step 5 is where the real data science work begins – where the data scientist starts using tools like SAS, SAS Miner, R, Mahout, MADlib, and Alpine Miner to build analytic models.  This is true science, baby!!  At this point, the data scientist will explore different analytic techniques and algorithms to try to create the most predictive models.  As my data scientist friend Wei Lin shared with me, this includes some of the following algorithmic techniques:

Markov chain, genetic algorithm, geo fencing, individualized modeling, propensity analysis, neural network, Bayesian reasoning, principal component analysis, singular value decomposition, optimization, linear programming, non-linear programming and more.

All in the name of trying to quantify cause-and-effect! I don’t suggest trying to win a game of chess against one these guys.

Step 6:  Ascertain Goodness of Fit.  Step 6 in the data science process is where the data scientist will try to ascertain the model’s goodness of fit. The goodness of fit of a statistical model describes how well the model fits a set of observations.  A number of different analytic techniques will be used to determine the goodness of fit including Kolmogorov–Smirnov test, Pearson’s chi-squared test, analysis of variance (ANOVA) and confusion (or error) matrix..


The data science process is highly collaborative; the more subject matter experts involved in the process, the better the resulting model.  And maybe even more importantly, involvement of the business users throughout the process ensures that the data scientists focuses on uncovering analytic insights that pass the S.A.M. test – Strategic (to the business), Actionable (insights that the organization can actually act on), and Material (where the value of acting on the insights is greater than the cost of acting on the insights).

[1] Disclaimer:  I serve on DataRPM’s Advisory Board


Bill Schmarzo

About Bill Schmarzo

CTO, Dell EMC Services (aka “Dean of Big Data”)

Bill Schmarzo, author of “Big Data: Understanding How Data Powers Big Business” and “Big Data MBA: Driving Business Strategies with Data Science”, is responsible for setting the strategy and defining the Big Data service offerings and capabilities for Dell EMC Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He’s written several white papers, is an avid blogger and is a frequent speaker on the use of Big Data and data science to power the organization’s key business initiatives. He is a University of San Francisco School of Management (SOM) Executive Fellow where he teaches the “Big Data MBA” course. Bill was ranked as #15 Big Data Influencer by Onalytica.

Bill has over three decades of experience in data warehousing, BI and analytics. Bill authored Dell EMC’s Vision Workshop methodology that links an organization’s strategic business initiatives with their supporting data and analytic requirements, and co-authored with Ralph Kimball a series of articles on analytic applications. Bill has served on The Data Warehouse Institute’s faculty as the head of the analytic applications curriculum.

Previously, Bill was the vice president of Analytics at Yahoo where he was responsible for the development of Yahoo’s Advertiser and Website analytics products, including the delivery of “actionable insights” through a holistic user experience. Before that, Bill oversaw the Analytic Applications business unit at Business Objects, including the development, marketing and sales of their industry-defining analytic applications.

Bill holds a masters degree in Business Administration from the University of Iowa and a Bachelor of Science degree in Mathematics, Computer Science and Business Administration from Coe College.

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7 thoughts on “Dynamic Duo of Analytic Power: Business Intelligence Analyst PLUS Data Scientist

  1. Perfectly summarizes the dichotomy between BI and today’s Data Scientists.
    Early BI practitioners were frustrated by the limits of SQL, schemas and tools. But it was the best they had. A regression analysis required multiple iterations of the database and schema in order to get data organized for the analysis.
    Today’s technology enables so much more flexibility based off of the raw data. Shortening cycle time and analysis.
    BI practitioners can’t allow their thinking to be limited by the BI tools they’ve grown up with!

    • CactusVin, well said. Doing regression analysis using SQL was nearly an impossible task, as you have described. In fact, one spent more time trying to get the schemas right instead of identifying the variables and metrics (and their associated transformations and enrichments) that created better predictions.

  2. Great article Bill. Clearly articulates the value of SQL based tools ( Hawq, Hive etc.) and Native on Hadoop tools (Platform etc. ) for those respective oersonas. Thanks

    • Amen Shailesh! Plus we have lots of BI and data warehouse folks who are already trained or skilled in SQL who all of a sudden can play in the big data workspace.

  3. In short, Business intelligence answers to the business questions using data while data science explores data for interesting patterns and predict answers today for tomorrow’s questions! Great read Bill Schmarzo!