In this blog post I discussed various building blocks which can help to establish and manifest an agile approach to Business Intelligence within an organisation. In this article I will focus on the aspect “Agile Mindset & Organisation”. The probing question is, which approach is best suited to develop a data warehouse (= DWH; not just the BI Frontend) incorporating the agile principles. Closely linked to this matter is the question of cutting user stories. Is it sensible to size a user story “end to end”, i.e. from the connection of the source, staging area and core DWH all the way to the output (e.g. a dashboard)? As you can imagine, the initial answer is “it depends”.
When looking at the question more closely, we can identify multiple factors that will have an impact on our decision.
First of all, I would like to point out the distinction of the following two cases of the development organisation:
- Organizational Structure A) DWH and BI Frontend are considered one application and are developed by the same team.
- Organizational Structure B) DWH und BI Frontend are considered as separate applications (while being loosely coupled systems) and developed by different teams.
Characteristics of the Organizational Culture
In a next step we need to differentiate between two possible characteristics of organizational culture, which are extracted from Michael Bischoff’s book “IT Manager, gefangen in Mediokristan”, (engl.: IT Manager, trapped in Mediokristan). A nice review of the book can be found in this blog entry (in German).
- „Mediokristan“: The „country“ Mediokristan is described as a sluggish environment where hierarchies and framework are predetermined, and risk- and management concepts are dominating factors. It stands symbolically for the experiences I have made in large corporate IT organizations. Everything moves at a slow pace, cycle times tend to be high; mediocrity is the highest standard.
- “Extremistan”: The “country” Extremistan is best described as the opposite of Mediokristan. New, innovative solutions are developed and implemented quickly, fostered by individual responsibility, self-organization and a start-up atmosphere. Its citizens strive for the extreme: extremely good, extremely flexible, regardless of the consequences. What works will be pursued further, what does not will be discontinued. Any form of regulation or framework is rejected extremely too in case they are seen to hinder innovation.
Needless to say, the two cultures described are extremes, there are various other characteristics between the two ends of the spectrum.
Alternatives to agile development approaches
The third distinction I would like to point out are the following two alternative approaches to agile development:
- Development Approach A) Single Iteration Approach (SIA): A number of user stories is selected in the beginning of an iteration (called a Sprint in the Scrum jargon), with the goal to have a potentially deployable result at the end of one iteration. With Organizational Structure A in place (see above), the user story will be cut “end to end” and has to encompass all aspects: Connecting the required source system (if not available already), data modeling, loading of the data into the staging layer, EDWH and data mart layer and last but not least creating a usable information product (e.g. a report or a dashboard). The processing of the user story also includes developing and carrying out tests, writing the appropriate documentation, etc. It is a very challenging approach and will generally require a Team of T-Skilled People, where each member of the team possesses the skills to manage and fulfil any and all of the upcoming tasks over the time.
- Development approach B) Pipelined Delivery Approach (PDA): The PDA exists because of the assumption that the SIA is illusive in many cases. One reason is the lack of T-Skilled people in our specialist driven industry, or the involvement of multiple teams (e.g. separate teams of Business Analysts, Testing) in the development process in extreme cases. Another reason is the mere complexity we often see in DWH solutions. An iteration cycle of two to four weeks is already quite ambitious when – in the figurative sense – doing business in Mediokristan.
As an alternative, PDA describes the creation of a DWH/BI solution based on a production line (also see the book written by Ralph Hughes: “Agile Data Warehousing Project Management: Business Intelligence Systems Using Scrum, Morgan Kaufmann, 2012). The production line (=pipeline) consists of at least three work stations: 1. Analysis & Design, 2. Development, 3. Testing. In the shown illustrations below (taken from a concrete customer project) I added a fourth station dedicated for the BI Frontend development. A user story runs through each work station in one iteration at the most. Ideally, the entire production line is run by the same team, which we will assume in the following example:
- The user stories that are to be tackled in the early stages are defined and prioritized during a regular story conference at the outset of a production cycle. They will thereafter be worked on in the first work station “Analysis & Design”. Evidently, in this initial phase, the pipeline as well as some members of the team are not used to full capacity. In accordance with the Inception Phase in the Disciplined Agile approach, these gaps in capacity can be used optimally for other tasks necessary at the beginning of a project.
- After the first iteration, the next set of user stories that will be worked on will be defined at the story conference and passed on to the first work station. Simultaneously, the user stories that were worked on in the first work station in the previous iteration will be passed on to the next one, the development station.
- After the second iteration, more user stories will be chosen out of the backlog and passed on to the first work station, while the previous sets will move further along the pipeline. Thus, the user stories of the first iteration will now be worked on in the testing work station. (One word re testing: Of course we test throughtout the development too! But why would we need a separate testing iteration then? The reason lies within the nature of a DWH, namley data: During the development iteration a developer will work and test with a limited set of (test) data. During the dedicated testing iteration full and in an ideal case production data will be processed over multiple days; something you can hardly do during development itself).
- Consequently, the pipeline will have produced “production ready” solutions for the first time after three iterations have passed. Once the pipeline has been filled, it will deliver working increments of the DWH solution after each iteration – similar to the SIA.
Pipelined Delivery Approach with four work stations
Testing inside one pipe cycle
The two approaches differ in the overall lead time of a user story between story conference and the ready-made solution, which tends to be shorter using the SIA in comparison to the PDA. What they have in common is the best practice of cutting user stories: They should always be vertical to the architecture layers, i.e. “end-to-end” from the integration of a source system up to the finished report (cf. organizational structure A) or at least the reporting layer within the DWH (cf. organizational structure B). While the PDA does incorporate all values and basic principles (this topic might be taken up in another article) of agile development, in case of doubt, the SIA is more flexible. However, put in practice, the SIA implementation is much more challenging and the temptation of cutting user stories per architectural layer (e.g. “Analysis Story”, “Staging Story”, “Datamart Story”, “Test Story”) rather than end-to-end is ever present.
When is which approach best suited?
Finally I would like to show where and how the above mentioned aspects are in correlation with each other.
Let’s have a look at “Organizational Structure A) DWH and BI Frontend are considered one application”. If the project team is working out of Extremistan and consists of mostly T-skilled team members, chances are that they will be able to implement a complete DWH/BI solution end-to-end working with the SIA. The success of the project with this approach is less likely, if large parts of the team are located in Mediokristan. Internal clarifications and dependencies will require additional time in matters of Analysis and Design. Furthermore, internal and legal governance regulations will have to be considered. Due to these factors, in my experience, the PDA has a better chance at success than the SIA when developing a DWH/Frontend in Mediokristan. Or, to put it more positively: Yes, Agile Development is possible even in Mediokristan.
The situation I have come across more often is „Organizational structure B) DWH and BI Frontend are considered two separate applications“. As a matter of principle, agile development with the SIA is simpler in the BI Frontend than the DWH backend development. That being said, the environment (Mediokristan vs. Extremistan) also has a great impact. It is possible to combine the two approaches (PDA for the DWH Backend, SIA for the BI Frontend), especially if the BI Frontend is already connected to an existing DWH and there is no need to adapt it according to every user story in the BI Frontend. Another interesting question in Organizational structure B) is how to cut the user stories in the DWH Backend. Does it make sense to formulate a user story when there is no concrete user at hand and the DWH is, in the practical sense, developed to establish a “basic information supply”? And if yes, how do we best go about it? An interesting approach in this case is the Feature Driven Development (FDD) approach, described in this Blog article of Agile-Visionary Mike Cohn. The adaption of the FDD approach when developing a DWH might be interesting material for a future article…
As you can see, the answer “It depends” mentioned at the beginning of this blog post is quite valid. What do you think? What is your experience with Agile BI in either Mediokristan or Extremistan? Please feel free to get in touch with me personally or respond with a comment to this blog post. I look forward to your responses and feedback.
(A preliminary version of this blog has been posted in German here. Many thanks to my teammate Nadine Wick for the translation of the text!)