Update: Albert D. Kallal has kindly started the discussion off, and to get some more opinions I'm adding a bounty.
This is a nontrivial question about maintenance of a legacy application myself and two other developers support. We are not the original developers, and the code base is 300,000 lines of MFC and business logic tightly coupled together. We don't know every single line of code 100%.
We do know the code behind the major components, and we know that it's poorly written. Our objective is to refactor the application out of 1995 and into 2010. Between the three of us there is (in aggregate) enough experience in software architecture and database design for us to fix the components that are poorly architected in code or incorrectly modelled in the database, but we don't have a lot of experience with modern reporting systems. Thus my question (once you get to the end of it...) is about reporting systems.
For anybody who reads this entire post, I am appreciative of your time. For anybody who reads this post and replies with solutions, experience (or sympathy!), I am both appreciative and thankful.
At work I have inherited the maintenance of an Access 2003 database that contains approximately 250 reports (and thousands of supporting queries) that acts as a reporting engine for our application.
The reports all have swathes of VBA in them for particular formatting or pulling extra information into the report. For this reason we are entirely locked into the Access platform, we can't use tools like BIDS to import the Access report objects without messing around to make the report display the same without VBA.
So to get ourselves out of this Access solution we need to put some time in going over every single report. Which means we're looking to pick the best longterm solution, since we're going to have to redevelop every report regardless of the platform we choose.
Furthermore our customers have a choice of Microsoft Access or SQL Server as their database. This means that all our SQL has to be written with the lowest common denominator in mind - JET SQL. We've got some wiggle room to drop support for Microsoft Access, but we'd need to build a case for it. If the best reporting system we can identify has strong support for SQL Server but little or no support for Microsoft Access this will accelerate us dropping support for Microsoft Access as a database.
The overall implementation of the report system is quite mediocre, when we want to display reports in our application we start a Microsoft Access process, find its window and reparent it to our application, strip off its window styles and then use the
Access.Application COM interface to invoke some VBA that creates linked tables to the database (either a Microsoft Access MDB or a SQL Server database) and then opens up the report we want. Probably the only supported part of the process is using the public COM interfaces, the rest is an ugly hack. The other components in the application are equally underwhelming.
To "fix" our application we've got a new development plan, with development of our application split into (approximately) three parts every year.
- 4 months upgrading our application to support the latest government legislation in our industry
- 4 months delivering a new major feature
- 4 months "consolidation" (fixing what is broken)
We're currently at #3 now (for this year), and we really want to take advantage of the downtime to fix up the application, refactoring the major components. We have three developers, and want AppName v5.0 out at the end of 2012 (it's currently AppName v4.12). This gives us 36 months of development effort to approportion between several components (user interface, underlying database structure, reporting, etc) over the three consolidation periods we will have before then. The sum of the components that we fix will give us v5.0.
We've scoped out what we'd like to do with most of the components except for our reporting engine, and I'm posting on SO in the hope of getting some good ideas, or at least a feel for the work that's required.
I have two ideas for improving our reporting system. Both of them involve a moderate amount of work, and there is one consideration that neither solution addresses completely: in addition to the reports that we develop, our customers also have the opportunity to request bespoke development of reports. They're customer-specific, we take their Access database, augment it with their report and give it back to the customer. There's hundreds of unique reports out there - unusable if we turned the old system off. (And we have to turn the old system off eventually - we don't know how much longer we're going to be able to mess around with the Microsoft Access window to make it look like an embedded report. We already have two distinct code paths for Access 2003 and 2007. What if we can't hack up a code path for Access 2010 and all our customers have to use Access 2007?)
For both ideas, the intention is to stop supporting our current reporting system and let it run for as long as it will without maintenance. Maybe we can hack in Access 2010 and Access 2014 support, and the customer reports that were developed keep putting along for 5 more years. Over time, we'd migrate the most commonly used reports from the old Access database into their new format.
The first idea is to write a wrapper around the
ReportViewer control as a replacement reporting engine.
We'd need to move the project to C++/CLI (already on the cards), and instead of having to launch an entire process each time we needed to view a report we could simply instantiate this control. A bonus of this that the
RDLC files that contain the reports are much easier to version control in Subversion than the Access 2003 database we currently have (we use Visual SourceSafe because the tools to integrate SVN with Access don't work well with the size of our Access database). The visual designer for
RDLC files is also nicely integrated into Visual Studio.
This is more of an evolutionary rather than revolutionary change to the way we do reports, the
ReportViewer control will take an
RDLC file that has the report layout, and our application will take care of querying the data. Because our database might be SQL Server or Microsoft Access, we still have to write simple JET SQL. We're gaining better reporting (drill down looks nice), stronger authoring tools and easier version control, but is this worth the effort?
Idea 2: SQL Server Reporting Services and SharePoint 2010 with Access Services
The second idea is to kill Access as a database platform and migrate all our customers to SQL Server (we have hosted instances of our application for those customers who don't have the skill set to set up their own SQL Server instances). Once they're migrated we would use SQL Server Reporting Services as the reporting engine, with the
ReportViewer control in server rendering mode.
In addition to SQL Server Reporting Services, I am curious as to whether SharePoint 2010 with Access Services could be used to rapidly migrate existing Access reports into a more manageable format. We'd take the Access report that the customer uses, convert it to an Access Web Report then make it available for them on a SharePoint site. This would only be for our hosted customers, but if we find a way to deal quickly massage the VBA out of customer reports we could churn through the several hundred custom reports our customers have.
I'm also interested in the ability to use an Access Web Navigation Form to act as a portal to all our reports. We'd host a web browser control inside our application which would give customers access to their own reports and to our standard suite.
We'd get all the benefits of Idea #1 plus the ability to write in full Transact SQL, a reports portal, and (hopefully) a reasonable upgrade path for customer's proprietary reports.
So, my question is: am I going about this the right way? Are these viable solutions for modern reporting systems, or laughable? We have a strong preference for using the
ReportViewer control either in client rendering mode where our application processes the data, or in server rendering mode in conjunction with SQL Server - but are there reporting systems like Crystal Reports which offer better reporting and better migration paths for our legacy Access reports?
If you had up to 36 months of developer time, how would you do this?
Well, ok, no one else jumping in, I give this a go.
Quite interesting how you talking about a report writer that 15+ years old. Back then the Access report writer was beyond state of the art. It was a country mile ahead of everything else in the industry. Even today a lot of competing report writers don't have the concept of sub reports that allows modeling of relational data without having to resort to code or even SQL. Then, throw in programmable VBA, then the result is something that's very unique and powerful.
For access 2007, the report writer received some more nice upgrades in terms of layout controls but that going to be of little help here.
And, for 2010 we can now display reports in a sub-form control. This feature was added to facilitate use of the new access navigation control. Access 2010 has a new web browser control (works in forms or reports), and there also a new navigation control. Your post hints that the new navigation control and the web control are somehow related to each other but they completely different features.
Both the new web browser control, and navigation control can be used in both web appliations or 100% client only applications. The navigation control is nice since you can build that nav contorl by drag and dropping reports onto the nav control to build up a up a list of reports to choose from (it is slick and easy and nice). And with this navigation control, we can actually build some nice drill down type of interfaces for reports.
As you noted for access 2010 we now have web publishing of access reports and this feature is based on SQL server reporting services (they are RDL reports). However, two important issues here is no VBA is allowed inside of the web reports. And, I also point out that there is no automatic conversion utility that is built into access that will convert existing reports into web based reports. So to build a report that's going to be designated and published to the web, you have to choose specifically to create a web report to accomplish this goal. So this answers and clears up one question of yours of will this help you convert existing reports to SQL server, and the answer is no. So, Access will not help you convert existing reports to web based RDL reports (As noted, Access uses RDL and sql reporting for those web reports - those reports also render in the access client side without conversion).
Access has a great path for web based reports via SharePoint and also Access Web is coming to Office 365. However, keep in mind this ability is not going to help much with the existing reports that you have.
In fact one of the things I would be looking at if you're going to use winforms report viewer is the change in where that existing VBA report code will be moved to? You not really mentioned this issue. As noted one really interesting and great feature of those reports is that imbedded VBA code. Often that VBA will have been used because SQL and something like RDL will NOT work because neither of those languages (sql, and RDL) are procedural code.
I can't stress how important this concept is. So, this quite much means any report writer replacements means that code will now have to be OUTSIDE of the reports and moved into your application. So, keep this issue in mind as now when you issue new reports, you also be issuing new procedural code that NOT be contained in those reports. This code will have to become part of your application (so, to issue new reports, you will thus also be issusing a new version of your software).
You are not likely to find much that allows procedural code to be imbedded inside the report like you can with access. So, that report code and logic will now have to be built and maintained within your main application and outside of the reports.
At the end of the day, I should point out the old adage if it ain't broke, then don't change it. Access been around for a very long time, but we seen significant investments from the folks in Redmond into this product during the last few years, so it shows no signs of dying anytime soon.
So, one possible suggestion is to keep the status quo, and continue going the way it works now. I mean you stated that you have to continue supporting JET for this anyway so you not getting away from having to use a major part of Access anyway. So, you continue to have to use JET engine anyway. So, you just dumping the report side and you still have use the JET data engine anyway.
However, assuming this decision's been made, I can't really suggest what report writer you should replace the access one with. Obviously considerations for the next report writer should have a seamless path to web even if they are NOW going to be rendered on the desktop. It makes no sense to make a large investment today without web considerations in some fashion.
I do think SQL server reporting services is a good choice due to the web ability. And, as an access developer we also have the option to create web based reports but they also render perfect in the access client on the desktop side (and this works when you have no server and no conversion issues exist when publishing these reports to the web, or using them local on the client). So, even if you don't use access, do choose something that allows reports to render both desktop and web like access 2010 allows.
I would consider building the report system around some .net tools. This would likely not play too well as an embedded report system inside of your existing application, but it would allow you to issue new reports, and you would not have to touch your existing code base for each new report issued. This issuing of new reports that have procedural code needs to be resolved. You likely can now issue new reports without having to modify the main application because those reports can contain code inside. I would be looking to use something that would allow new reports to be built and issued but you not having to issue new edition of your main software. You might not embeed the code in the reports anymore, but you need to palce it somewhere, and hopefully outside of your main application.