Cognos Analytics, or CA for short, is an enterprise level reporting platform. At the most basic level you can use it to build reports. But taking a broader look allows you to see that it covers a vast amount of ground through many different modules.
The basic platform comes with several meta-modelling tools.
Framework Manager allows you to build relationships between physical database tables, and even a ROLAP solution. Great for detailed or minor aggregation.
Transformer is a basic cube modeling software. Best for building dimensional models over smaller datasets (a few dozen GB), it works extremely well.
Dynamic Cubes is a more advanced ROLAP solution that has intelligent aggregate, query, data, and result set caching. In my experience this works best with larger data, in the TB or PB ranges.
Data Modules. This is an advanced user level modelling. It allows end users to build and cache datasets which they can then use in ad-hoc dashboards and reports.
On the reporting side it, again, has a few tools.
Report Studio is the professional reporting environment. This allows BI Developers to create advanced reports, dashboards, analytical applications. While it does take some training, the effort is well worth it.
Dashboards work against the data modules. T allows advanced users to work with the data modules they've built previously to build dashboards. Users can quickly drag in fields directly onto the canvas to make graphs, prompts, data grids. Interactivity is automatically defined (but can be defined manually) to allow users to filter one group of objects by clicking on another.
Story is a tool used to create presentations. You can use elements from other reports to make a slide show or "guided journey".
There are a few other tools, like Event Studio which can be set to automatically perform actions based on query outputs. There is a graph building tool that allows you to build graphs that developers can use in their reports.
Improvements to My Organization
As a consultant, I've had the pleasure of working with a very wide range of clients with very specific needs. So far, Cognos has not failed to meet their needs, and surpass their expectations. The beautiful thing about Cognos is its flexibility.
One client, a government research organization, uses the tool to track specific incidents. When certain criteria occur, specific reports should be emailed. An SMS should be delivered. The researchers needed to be able to view the incidents from as many different perspectives as possible, and quickly go from one perspective to another without losing the context. Dynamic filtering and linking prevailed here.
Another client wanted to expose Cognos to the general public, embedding report outputs in their own portal system. This required a heavy security presence, with redundant levels of data and object security. Even if a report developer did leave a hole in the report, malicious end-users would never be able to get any data they weren't permitted to see. Cognos withstood the probing of professional pen-testers with admirable results.
Room for Improvement
As with all products, I have run into bugs; some severe enough to derail the project until IBM provided a patch. IBM Support can be slow at times, but they can usually deliver in a timely manner. Fortunately, show-stopping bugs are few and far between.
Use of Solution
I have worked with IBM Cognos for many years, across several different product versions. The most recent being IBM Cognos Analytics 11.6.
Cognos presents interesting scaling opportunities. Additional servers can be loaded and unloaded as needed, and there are many ways of routing report runs. For larger organizations, it's possible to optimize report runs by having one branch of an organization always run reports from a single server.
Customer Service and Technical Support
Support is not cheap, and consultants (hello!) generally charge a few appendages. This is, of course, a matter of getting what you pay for.
The best piece of advice I can give to companies considering Cognos is to factor in the cost of training or consultants. Cognos, despite what some sales people may say, is not an easy tool to start with. It requires a hefty amount of investment to implement. But with proper training, and working with the tool's strengths, the return is well worth the price.
Disclosure: I am a real user, and this review is based on my own experience and opinions.