score:5
Yes, you can use the e-Service for business trips, and in fact I did just this for a colleague who needed to visit Singapore last month. It was issued in under 48 hours, making this much faster and more convenient than the embassy application route, particularly since you don't need to wait for an appointment.
There are actually two options: the company can sponsor the visa via CorpPass (guide PDF), or an individual working at the company can sponsor it (guide PDF). I would recommend the corporate path if your company is flexible enough to handle it, but somebody with CorpPass logins has to do it and typically this access is limited to HR/accounting. We ended up getting an individual to do it, and this too was fine.