Jitterbit vs. BizTalk - interface

Is there anyone who has used or looked into using Jitterbit as well as BizTalk? If so, what are some pros and cons of each, and which one did you go with as your final solution?
Specifically, I'm looking for SAP integration, but any input would be appreciated.

Like Rob I have not heard about JitterBit until reading your question (thanks!), I have, however, been working with BizTalk, almost exclusively, for the past 9 years; for that reason I wasn't sure I should be responding, but as Rob did, and nobody else has, I figured it's worth a couple of cents....
From the little reading I've done it seems to me that JitterBit, apart from being an open source, which has it's pros and cons, is trying to lower the entry barrier by offering a relative simple solution with the promise of rapid development and drag-n-drop approach "with no custom code".
I'll take their promise at face value, as I know nothing about it, although I have my doubts, so let's assume developing with JitterBit is really easy, there's one thing I can clearly state - developing with BizTalk isn't.
But, and that's a bit but in my view, developing with BizTalk is somewhat difficult not because Microsoft did a bad job at it, on the contrary - developing with BizTalk is somewhat difficult because Microsoft wanted to create a tool that could realistically allow enterprises to solve their BPM and integration needs well, and, in my experience, these problems are almost never simple, so Microsoft had built a server that has many capabilities, is very strong and very flexible, at the cost of complexity.
So, while any experienced technical sales guy can give you a demo of an integration scenario that is very simple, and is developed in a few minutes using a lot of drag and drop and configuration, even in BizTalk, but is this a realistic enterprise-level solution? was it a realistic scenario that was demonstrated? from my experience the answer is almost exclusively no; the problems tend to be complex, and their require a more robust solution.
So, I guess the bottom line would be - if you're looking for a one off solution, and open source is something you guys work with - JitterBit is definitely worth looking at, seeing if it's capable of helping out and has, indeed, a short learning curve (it would be important to look at maintenance, monitoring, trouble shooting, instance management etc)
If, however, you believe, as is often the case, that your solution would grow to become a BPM/integration platform in your organisation, and you need something more robust - I would put my money on BizTalk being a better candidate.

I've done a fair bit of integration with SAP, starting with the old SAP DCOM connector. More recently I've been involved in the selection of an integration platform to serve in an Enterprise Service Bus pattern.
We did web service samples to connect to SAP on a number of platforms, including BizTalk, Mule, Netweaver, Webmethods and Tibco. Webmethods won out based on licensing and capability, though BizTalk and Netweaver both had very high marks.
Jitterbit was not part of the evaluation - in fact I had to look it up to be sure I understood your question.
If your goal is just to be able to call an RFC, the .NET SAP connector works well.
If your goal is to expose a web service to wrapper a process in SAP, then BizTalk is good, but I recommend you see if your organization already has netweaver licensed as there are many web services available directly from SAP with no coding.
My recommendation is to avoid Jitterbug and Mule for the enterprise for now - unless Open Source is actually a popular thing at your place of employment. Netweaver and BizTalk are very robust, polished products.
If you are looking for something you can ship easily, then Jitterbug may make more sense. Though generally I'd recommend you define it as a web service call, and look to your customers technology stack for the most appropriate integration technique.
More context of what you are looking to achieve will enable a more accurate answer.

Michael,
We use Jitterbit in our organization and we've been very successful with it in various projects. Our SAP projects use XI and Jitterbit has dramatically simplified the ability to integrate web service interfaces with the various protocols it supports.
In addition to an excellent price (and we now subscribe to Jitterbit for support) we realize great value out of the support service. If we have any questions during our implementations they seem to provide all the subject matter expertise included in the support cost, so we're quite self sufficient.
We still have many other integration solutions in our company including VB and Java programs; it's a mess, but we don't believe that any one platform will meet all of our different divisions' needs. We have been using open source, specifically Linux and Apache for many years now, although IBM and Microsoft are also prevalent here.
We went with Jitterbit as it supports protocols needed to integrate any modern system and with SOA / Web Services being our stated direction Jitterbit was a great fit for what we needed.
Given that Jitterbit is Open Source, I would encourage you to download it and try it out.

I will say it simply, I have been using biztalk and was one of the people that helped validate the 2006 training course. Biztalk by far one the best server applications for Business process that is available today. You do also have to factor in the price point is ridiculously low compared to what else is out there.

Related

General architecture for backend?

We are trying to be forward looking in our architecture choice on some of the new systems we are designing. Pretty much we want to architecture back end system that no matter what interface we decide to use (WinForms, Silverlight, MVC, Webforms, WPF, IOS (IPad/Iphone), ect...) which i believe just screams REST. Our organization generally will only use Microsoft APIs but since i have no idea when WCF-Web-Api will be released and we want to get started soon it looks like we have no other choice.
We want to take baby steps here to increase the chances of buy off. So we don't want to have to set up another server with IIS.
In the foreseeable future we will only be using WinForms & WebForms. What i was thinking we could use Nancy on the local machine but communicate with it in a RESTFul way. That way in the future it should be as simple as setting up a server and redirecting all the clients to that server rather than locally.
I've never used either NancyFX or OpenRasta, but, from what ive heard, it sounded like a good fit.
So the questions are:
Is the way i'm thinking on approaching this a good approach
Does it sound like NancyFX or OpenRasta would be a better fit?
Any reason why we should wait for WCF-Web-API and if so does anyone have an approx release date.
OpenRasta was built for resource-oriented scenarios. You can achieve the same thing with any other frameworks (with more or less pain). OpenRasta gives you a fully-composited, IoC friendly environment that completely decouples handlers and whatever renders them (which makes it different from MVC frameworks like nancy and MVC).
I'd add that we have a very strong community, a stable codebase and we've been in this for quite a few years, we're building 2.1 and 3.0 and our featureset is still above and beyond what you can get from most other systems. Compare this to most of the frameworks you've highlighted, where none have reached 1.0.
Professional support is also available, if that's a deciding factor for your company.
But to answer your question fully, depending on your scenario and what you want to achieve, you can make anything fits, given enough work. I'd suggest reformulating your question in terms of architecture rather than in terms of frameworks.

Is WebService the next Big thing?

I was today trying to figure out on working with WebService and found many articles really gospel over the Web Service and its effectiveness in the Market share.
My Questions are:
For a Complex project of critical data, is it better to opt for WebService?
What Makes WebService different from other way of fetching the data?
The answer is... it depends. Web services are not really the next Big thing, they have been a Huge Thing for years now. In business applications, web services allow a big level of interoperability and capabilities never seen before.
They help integration with legacy systems, cooperation between distinct departments, defining loosely coupled interfaces and such. You should read some about Service-oriented architecture.
If all you need is a PHP application that handles data from a single database, you might not need web services at all. If you are designing a solution that revolves around multiple data sources, with complex security involved, multiple languages and/or multiple applications, then web services become essential.
SOAP is a protocol; if working with PHP, you'll need to check out the PHP: SOAP guide to understand how it works. For every language (almost), there are existing APIs to develop web services. Anyhow you might want to check RESTful web services instead of SOAP-based ones, they are generally simpler to implement/understand. But that's another debate ;-).
Cheers.
That mostly depends on the definition of "big thing".
My experience with the WS stack and SOAP and all the acronym soup is that it takes an awful lot of workforce to deploy it. The status of the frameworks is complex, and definitely not something a hobbyist can put to work in a couple of afternoons. We have seen how many things on the net became the next big thing just because they were easy. Easy to understand, easy to interact with, easy in technology. Wikipedia, twitter, digg, youtube are internet big things, and they are, from the interaction point of view, light years away from SOAP/WS based interaction. They are KISS: simple and stupid. A whole horizontal market was opened just because of their simplicity. Even multiprocessing platforms like BOINC don't use anything near the WS stack, but they are the core of many high-throughput efforts.
Now, if you have to deal with complex multi-host transactions, authentication, credential delegation, caching... WS is there. It's the target that makes the need: banks, flight reservation, stuff like this. but they won't impact the common programmer. They require too much energy and too many different competences at once to become something usable for a horizontal market of developers.
Also, I am a REST person. I never advocated SOAP with much emphasis, but there was nothing else and it was a better evolution over XMLRPC (which, if you have to perform dumb RPC, IMHO it's still a good choice). Now I changed my mind. You mostly have resources on the web, and you interact with them with HTTP methods. SOAP is nothing but RPC on hypersteroids. No, REST is not the solution that replaces WS. At all. it's simply easier to use and to debug, albeit more difficult to design (you have to think in terms of resources instead of method calls). It's KISS. That's why it has more chances for success on the horizontal market.
It depends.
Web services can be useful if you need to expose the data across security boundaries, where a direct connection to an RDBMS would be a bad idea.
Popular method for implementing web services nowdays is to use RESTful API (eg. via Ajax/JSON). It's already "next big thing" – almost every major player has been offering it for years. Google, Flickr, Twitter, you name it.
The big advantage is that they help to implement an API layer.
If you implement your solution using a "bus" where the web services sit, it opens up your product to a far greater range of users and moves away from being a proprietary product.
It also enables people to interface using a wide range of solutions e.g web service clients can be implemented using command line, Jsp, Java, Asp, .NET, PHP etc.
They also enable code re-use e.g. if you implement GetClientDetails (ID) as a web service for one user, when the next group comes along wanting the same thing, all you have to do is give them the WSDL and they are away.

Should developer tools, languages, frameworks, etc. be standardized across an organization? [closed]

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The organization that I currently work for seems to be heading in the direction of dictating to software developers which tools, languages, frameworks, etc. must be used. However, nobody has convinced me that this is a good thing. The main argument I have heard is that it will make training easier. But, after developing software for over 10 years, I've never relied on training to learn how to use an IDE, programming language, or anything else; so I just can't relate.
With the rapid speed at which technology evolves, and the s-l-o-w-n-e-s-s at which I know the standards will adapt, I am concerned that my customers will have requirements that I won't be able to easily implement or won't be able to implement as efficiently as I should. For example, if there is a UI requirement for an auto-complete feature in a web app, and no API has been approved for this yet, I would need to implement auto-complete myself as opposed to using one of the many APIs that provide it out of the box.
A more radical example is if my customers wanted to have Google Wave features. In that case I would want the flexibility of configuring my development environment (including the IDE) and selecting appropriate frameworks (ex: GWT) to use.
Please provide feedback on whether or not you think that software developer tools, languages, etc should be standardized and a few points to support your argument.
There is a lot of benefit for standardization. My organization has fairly set standards on what technology we will use. We realize strong benefits in the following areas ...
Hiring. It is easy to describe what technologies we are looking for and make sure our recruiters are looking for the right people.
License/Software costs. I can buy enterprise licenses easily. It gives me the opportunity to keep costs down by letting me spend more with a smaller number of vendors and thus get more leverage.
Consistency of delivery. Our teams have a very good idea of what projects will take to build, rollout and maintain because they have done it with success before (and they know the pitfalls too).
Agility. I can have one team take over for another or one individual take over for another more easily because of standardization.
Quality. We have peer reviews across teams as well as QA across teams.
Without a consistent use of a technology stack, tools, languages and frameworks, these types of benefits would be more difficult to realize. I am not closed off to new technologies, but there has to be a concrete reason beyond "what if I want to ..."
A major issue with standardization is that once standards are out there, they get stamped in concrete and are difficult to change. This is why our corporate IT environment is stuck on IE 6, and the best change control system we have access to is CVS. Given this situation, some developers break the rules, and some find jobs at more innovative companies.
You have a mixed bag here.
I wouldn't standardize on IDEs, because every developer works differently. Those who are insanely proficient in emacs may see their performance suffer if forced to use Visual Studio. I optimize my Visual Studio experience with a 30" monitor and find it incredibly productive.
However, standardizing on some tools, such as SCons or make or something to build products is perfectly reasonable.
Banning some libraries and having a process where new libraries are either approved or not is also very reasonable. I know lots of companies that ban boost, or JQuery, or ban open source libraries in general, etc. And they had good reasons for doing it. I know I got fairly upset when an intern incorporated some random "security" library he found on the internet without running it by anyone.
In the end every company is different. You have to be standardized enough to avoid serious complications and issues as people come and go, or as new products are formed and organizational structures change. But you have to be flexible enough to avoid re-inventing every wheel you need.
The important thing is to have clear reasons for adopting a certain tool or banning some other tool or library. You can't just have management dictate that thou shalt use this and not that without consulting the engineering team and making the decision for good reasons. And once decisions are made those reasons should be written down and clearly communicated.
And also, if, in the end, your favorite tool or library isn't adopted, please don't whine about it. Be adaptable and do your job, or find a new one that makes you happier.
I once worked for a manager who felt the need to innovate at every level of his software development operation. Every development tool had to be cutting edge (preferably in beta). Many of the tools he asked us to use didn't have good documentation, and training was not available. Ultimately, most of the technology we tried simply didn't work. We wasted a lot of time churning through new technologies, only to dump them when it became clear we couldn't make progress.
I tried to make the case that innovation is perfect in the area where your value proposition lies. Innovation can also be used judiciously where standard techniques fail. But for most mundane tasks, using tried-and-true tools and methods should be the default. Less risk, less cost, less management attention needed. So you can focus time and energy on the areas where innovation has the most benefit.
So I think standardization has an important role. But blindly saying everything must be standard is just as sure to fail as my manager who thought everything must be innovative.
The number one argument in favor of standardization is that it maximizes the ability of the organization as a whole to use a common body of knowledge. Don't know how custom web controls are built in ASP.NET/C#? Ask Bill down the hall who has the knowledge. If you use different tools, such organizational wisdom is cut off at the knees. While it is not good to be restricted to a least common denominator (and hopefully your management will realize this) you should not overlook the benefits of shared experience!
UPDATE: I do not agree that innovation and standardization are polar opposites. Indeed, would we have nearly the level of web innovation if we still had the mishmash of networking standards characteristic of the 1980s? No we would not. Of course, we might have more innovation on new low-level networking protocols but is that really worth it? In its place, we've had an explosion of creativity within the bounds of TCP/IP and the Web standards (http, html, etc.)
The trick is knowing how to standardize without using it as an argument for closing down all new exploration. For example, we use only ASP.NET/C#/SQL Server in my company but I'm perfectly open to the use of new tools within this framework (we recently adopted the DevExpress reporting package, for example, supplanting the earlier standard).
Standardization is a must for a productive development team. However that doesn't mean that you can't revist the standards from time to time to adjust them to new technologies and trends.
Whether you develop operations software for internal clients, or products for external clients, there is no compelling reason not to standardize. You certainly did not give one.
Had you seen how companies are struggling with holding heterogenous products together that have been maintained for 10 years or more, and are now a conglomerate of various technologies that developers at some point thought made sense, you would not have asked this question.
From the top of my head, I could name at least 2 well-known software companies that will be driven out of business because their cost of maintenance has become so high that they can no longer compete (but I won't).
I think the misconception here is that suppressing individualism would supress innovation. That is simply not true. It is poor technical leadership that suppresses innovation.
One unpleasant consequence of standardization is that it tends to stifle innovation.
Innovation is scary. It involves cost and risk.
Standardization is not scary. It reduces cost and risk in the short term. Until your competitors have created a game-changing innovation. Then standardization is very costly.
It depends on the organization I think. One like Microsoft, yes, there should be a bit of a standard. A small business with one IT department, no. A larger business with several offices around the world ... maybe.
it all depends :-P
Assuming the organization has a broad suite of enterprise applications to manage, I'd say no for the following reasons, though I may be taking the message of everything being the same a bit too literally:
Compromise on using best-of-breed for systems, e.g. if all the databases are to be MS-SQL then any Oracle DB solution is thrown out. This would also apply to the fact that everyone using an IDE has to use the same one whether they be doing Data Warehouse report development, web applications, console applications or winForms. I'm thinking of systems like ERP, CRM, SCM, CMS, SSO and various other TLAs, FLAs, and SLAs. (LA = Letter acronyms for a decoding hint if you need it)
Upgrading by committee is another interesting issue. Where if each team can choose their tools and have one person that decides it is to upgrade things, e.g. start using Visual Studio 2008 instead of Visual Studio 2005, now have to determine at what threshold is it worth it to upgrade everyone simultaneously which may be a big headache if there are more than a few developers. For example, over the past 10 years when would there be IDE changes, framework changes, etc.?
Exceptions to the standards. Could a contractor bring in something not used in the organization if they believe it helps them build better software, e.g. Resharper or other add-ons that some contractors believe are very worthwhile that the organization doesn't want to spend the money to get? What about legacy systems that may make the standard become a bit unwieldy, e.g. this was built in ASP.Net 1.1 and so everyone has to have VS 2003 installed even if most will never use it?
Just my thoughts on this.
There are several good reasons to standardize.
First, it allows the enterprise better organizational flexibility, if everybody is more or less familiar with the same things. It also allows people to help each other better. I can't help with problems in the ASP.NET stuff, and there's not all that many people who can help me on the C++ side.
Second, it reduces support problems and expenses. Oracle and SQL Server are both decent products, but using both for similar functions is only going to cause problems. Not to mention that I've been in shops using several widely different platforms to do similar things, and it wasn't fun.
Third, there are some things that just have to be standardized. We couldn't operate half with VS 2005 and VS 2008, since we keep project files under source control. We had to pick a time and convert over.
Fourth, in some businesses, it simplifies the regulatory problems. I don't know what business you're in. I work at a place where we can get away with making mistakes right now, but I've also contracted at a bank and a utility, where it's necessary to be able to show auditors that everything is going in a standard way.
Fifth, it can simplify procurement, if you're dealing with software that costs money.
This doesn't particularly limit us, since if there's something we need that isn't standardized on we just go ahead and get it or do it.
If you want to make a business case against standardization, you'll need to have a business-related argument. Your argument seems to be that you won't be able to implement features the user wants, and that is a consideration. Got another argument?
There's nothing wrong with standardizing on an IDE that is rich enough to be configured for individual developers.
However, do make sure that you don't prevent individual developers from using additional tools, as long as the tools are licensed and that the use of the tool by one developer doesn't require all other developers to use it.
For instance, I happen to use NORMA to help me design databases. The output is SQL Server DDL (or anything else I want). I can make the DDL part of the project without making my NORMA source part of it. Later developers do not need to use NORMA to work on the project.
On the other hand, if I decided to use the Configuration Section Designer to create configuration sections, then future developers would also have to use it. A decision would need to be made about whether to use that tool.
The company I work for uses C#, ASP.NET, JavaScript and generates HTML. The advantages over and above those mentioned above are that there is a perception of improved velocity for maintenance and adaptive changes. The disadvantages include generating some boredom for people who are technically savvy (geeky) and prefer to use a mix and match of languages, depending on what they fancy is better suited, or for 'performance reasons'.
Technical and personal supervision is always good to have when you are developing as fast as you can to meet tight deadlines and competing in a highly saturated market for web development.

productivity superstar frameworks/tools for side gigs

If you were going to start building web sites as a consulting business on the side -- keeping your day job -- and you also had a toddler and a wife, what frameworks/tools would you pick to save you typing?
Any language.
I'm looking for a productivity superstar stack that won't tie my hands too much when I have to update the site 6 months later, or "evolve" the data model once in production.
It needs to allow me to say "yes" to the client: community features, CMS, security, moderation, AJAX, ...
I would suggest Django. Super simple to get something up and running really quick. You are using Python which has a large library to go with it. For me Ruby on Rails would be a close second.
I'd probably look at DotNetNuke. Its easy to set up (a lot of hosts will do it for you) and easy to use and put together a custom site that business's will be able to maintain in the future.
Its fairly easy to create custom modules that are specific to a business and hundreds of modules for sale (or free) that can be integrated into DNN for special uses.
Take a look at Microsoft's Sharepoint server if you'd like a pre-made framework with many options for plugging in your own code. Sharepoint is kind of a world unto itself but it is a very powerful environment.
Update: I'm surprised to have been voted down on this one. Keep in mind that the questioner specifically requested frameworks that included a CMS. Sharepoint meets this criteria - unlike straight .NET or other web development frameworks.
If you are going to vote the entry down, I think you owe it to the person who asked the question to explain why you don't think he should not even explore it as an option. You could be right - collective wisdom is what voting on SO is all about. But without an explanation, we don't know why you think you are right.
My answers are going to revolve around the .NET stack.
Use Master pages and CSS templates. This makes it so much easier to pop in a new look and feel for your customer.
For sure I'd include the Dynamic Data framework in the .NET world.
Hosting might become an issue for your customer. Questions around managing email addresses, procedures on how to quickly update the website to include the new contact phone number (different for each customer, I'd assume) Consider getting a reseller account on your favorite webhost, and dole out webhosting accounts as appropriate. There are lots of issues around this point. It may turn out to be a nice source of recurring revenue.
Build yourself a few patterns including a database wrapper which would handle all your data calls (i.e. a dll which wraps all your data calls, sets up your ADO.NET objects, runs your sproc calls, and picks up the connstring from app.config or something similar.)
This goes a long way to maintainability as well.
I would recomend going with anything MVC in a language you can undertand! Theres a couple of CMS's in python, php and ruby using that design and well... that allows you to be ready for combat for Ajax and expanding anything very fast.
This is definitely not a question that can be answered.
I prefer asp.net webforms because I think it allows for extremely rapid web app development, but I am sure you will receive recommendations for:
asp.net mvc
Ruby on Rails
PHP and some framework
Python and some framework such as Django
I believe PHP has the most pre-built apps that you can use, though asp.net also has the things you are looking for.
All of these platforms and frameworks can do what you want.
Choose between Rails and Django. They both have different strengths. I like Rails better in general, but Django's admin interface can save you a lot of time when you need it.
There's another factor to take into consideration here: what are you the most familiar with? I believe that some studies have found upwards of a 30% loss of productivity when trying to learn a new language/framework.
Sometimes, there's nothing wrong with just sticking to what you know. But if you're interested in what languages/frameworks to learn, I'll refer you to the other posts because the above was the only thing I really have to add.
I recommend looking into Grails. It uses Groovy which is similiar to Java (so if you know this already you're good to go). Groovy runs on the JVM so you can still use all the great libraries already available for Java. Yet, since it's a dynamic language with a lot of the similar bells and whistles like Ruby you can use closures and that kind of neat stuff when you need/want to. And you're not slowed down by Java's traditonal slow compile-deploy-test development cycle.
Grails is already setup with Hibernate and Spring. You can create CRUD application in practically no-time (pretty much like Rails applications), and at the same time drill down and be able to control every little details since it's built on such proven and well-supported technologies. In addition there's literally hundreds of plugins available that helps you easily set up things like mailing lists, security, AJAX components and so on.
Otherwise, if you want to set up a community site and don't want to code a single line you could always check out ning.com.

How do I plan an enterprise level web application?

I'm at a point in my freelance career where I've developed several web applications for small to medium sized businesses that support things such as project management, booking/reservations, and email management.
I like the work but find that eventually my applications get to a point where the overhear for maintenance is very high. I look back at code I wrote 6 months ago and find I have to spend a while just relearning how I originally coded it before I can make a fix or feature additions. I do try to practice using frameworks (I've used Zend Framework before, and am considering Django for my next project)
What techniques or strategies do you use to plan out an application that is capable of handling a lot of users without breaking and still keeping the code clean enough to maintain easily?
If anyone has any books or articles they could recommend, that would be greatly appreciated as well.
Although there are certainly good articles on that topic, none of them is a substitute of real-world experience.
Maintainability is nothing you can plan straight ahead, except on very small projects. It is something you need to take care of during the whole project. In fact, creating loads of classes and infrastructure code in advance can produce code which is even harder to understand than naive spaghetti code.
So my advise is to clean up your existing projects, by continuously refactoring them. Look at the parts which were a pain to change, and strive for simpler solutions that are easier to understand and to adjust. If the code is even too bad for that, consider rewriting it from scratch.
Don't start new projects and expect them to succeed, just because your read some more articles or used a new framework. Instead, identify the failures of your existing projects and fix their specific problems. Whenever you need to change your code, ask yourself how to restructure it to support similar changes in the future. This is what you need to do anyway, because there will be similar changes in the future.
By doing those refactorings you'll stumble across various specific questions you can ask and read articles about. That way you'll learn more than by just asking general questions and reading general articles about maintenance and frameworks.
Start cleaning up your code today. Don't defer it to your future projects.
(The same is true for documentation. Everyone's first docs were very bad. After several months they turn out to be too verbose and filled with unimportant stuff. So complement the documentation with solutions to the problems you really had, because chances are good that next year you'll be confronted with a similar problem. Those experiences will improve your writing style more than any "how to write good" style guide.)
I'd honestly recommend looking at Martin Fowlers Patterns of Enterprise Application Architecture. It discusses a lot of ways to make your application more organized and maintainable. In addition, I would recommend using unit testing to give you better comprehension of your code. Kent Beck's book on Test Driven Development is a great resource for learning how to address change to your code through unit tests.
To improve the maintainability you could:
If you are the sole developer then adopt a coding style and stick to it. That will give you confidence later when navigating through your own code about things you could have possibly done and the things that you absolutely wouldn't. Being confident where to look and what to look for and what not to look for will save you a lot of time.
Always take time to bring documentation up to date. Include the task into development plan; include that time into the plan as part any of change or new feature.
Keep documentation balanced: some high level diagrams, meaningful comments. Best comments tell that cannot be read from the code itself. Like business reasons or "whys" behind certain chunks of code.
Include into the plan the effort to keep code structure, folder names, namespaces, object, variable and routine names up to date and reflective of what they actually do. This will go a long way in improving maintainability. Always call a spade "spade". Avoid large chunks of code, structure it by means available within your language of choice, give chunks meaningful names.
Low coupling and high coherency. Make sure you up to date with techniques of achieving these: design by contract, dependency injection, aspects, design patterns etc.
From task management point of view you should estimate more time and charge higher rate for non-continuous pieces of work. Do not hesitate to make customer aware that you need extra time to do small non-continuous changes spread over time as opposed to bigger continuous projects and ongoing maintenance since the administration and analysis overhead is greater (you need to manage and analyse each change including impact on the existing system separately). One benefit your customer is going to get is greater life expectancy of the system. The other is accurate documentation that will preserve their option to seek someone else's help should they decide to do so. Both protect customer investment and are strong selling points.
Use source control if you don't do that already
Keep a detailed log of everything done for the customer plus any important communication (a simple computer or paper based CMS). Refresh your memory before each assignment.
Keep a log of issues left open, ideas, suggestions per customer; again refresh your memory before beginning an assignment.
Plan ahead how the post-implementation support is going to be conducted, discuss with the customer. Make your systems are easy to maintain. Plan for parameterisation, monitoring tools, in-build sanity checks. Sell post-implementation support to customer as part of the initial contract.
Expand by hiring, even if you need someone just to provide that post-implementation support, do the admin bits.
Recommended reading:
"Code Complete" by Steve Mcconnell
Anything on design patterns are included into the list of recommended reading.
The most important advice I can give having helped grow an old web application into an extremely high available, high demand web application is to encapsulate everything. - in particular
Use good MVC principles and frameworks to separate your view layer from your business logic and data model.
Use a robust persistance layer to not couple your business logic to your data model
Plan for statelessness and asynchronous behaviour.
Here is an excellent article on how eBay tackles these problems
http://www.infoq.com/articles/ebay-scalability-best-practices
Use a framework / MVC system. The more organised and centralized your code is the better.
Try using Memcache. PHP has a built in extension for it, it takes about ten minutes to set up and another twenty to put in your application. You can cache whatever you want to it - I cache all my database records in it - for every application. It does wanders.
I would recommend using a source control system such as Subversion if you aren't already.
You should consider maybe using SharePoint. It's an environment that is already designed to do all you have mentioned, and has many other features you maybe haven't thought about (but maybe you will need in the future :-) )
Here's some information from the official site.
There are 2 different SharePoint environments you can use: Windows Sharepoint Services (WSS) or Microsoft Office Sharepoint Server (MOSS). WSS is free and ships with Windows Server 2003, while MOSS isn't free, but has much more features and covers almost all you enterprise's needs.