ALE technology is the standard in an SAP implementation, it reduces development efforts, speeds up implementation time and reduces implementation costs. Topics covered in this book include adding new EDI messages or interfaces to existing implementation.
This book is quite useful for me to learn about ALE, IDE and IDoc concept in SAP. The way it describes is very clear and systematic. And sometime there is repetition in two and more chapters (but I find it useful to memorize the important concept).
The only thing that I regret is that this technology is quite old and start to be left and replaced by new one. I am really sad to know that new knowledge that I learn is potentially unused in recent years. But life must go on. I still think that it's really good to learn many new things.