How to Handle Multiple Customers

Some time ago I wrote a blog post on how to do resource planning when you’re dealing with multiple small projects. It seems to be a tough problem, as I noticed many people are struggling with it.

To cope with such a situation, some experts will tell you that you should try and prevent working on multiple projects. Unfortunately, for people working on small projects, such advice is both true and useless at the same time, as many of us are not in a position to tell customer A that he should stop bothering you until you’ve finished the work for customer B. Optimizing just one customer’s happiness will get you out of business in no-time!

The solution is to make all customers just a little bit happier.

The only way to deal with this multi-tasking problem is to applying rigorous discipline to your weekly schedule. You must make it clear (to yourself and to your customers) how much time you can make available for which projects. Not doing so results in overcommitment to one (spoiled) customer, while the other customers suffer from neglect.

Here I give you an example, showing you how to handle scheduling with multiple customers. It might be a bit extreme, but it reflects the most common situations I have encountered in our own organization:


Suppose you are working on some big project (A) that requires as much attention as you can afford. How much time do you think you will have available in a period of four weeks? 160 hours? 120 hours? 100 hours? What will you say when the ScrumMaster asks you how much work you can do in the next sprint? If you do not carefully schedule all your other responsibilities, you could think that you have 160 hours available in four weeks.


Figure 1: four full weeks allocated to one big project

However, you might recently have worked on another big project (B). If you’re a bit like me, the product you delivered will still have a (small) number of bugs, flaws and other problems that need to be resolved right after the first release. In our organization we call this the “aftercare” phase, which is like a warranty on our products. The customer is entitled to have all problems fixed that are discovered within a few weeks after a product’s first release. You have to reserve some time in your schedule to take care of the aftercare phase.


Figure 2: warranty period for B takes some hours away from A

You may also have contributed to some older projects. It is said that good products require more maintenance, because users often request more improvements in products that they really like. Those earlier customers, the ones you helped by giving them some really stunning products, will keep asking you to add and change features. Provided these customers have some sort of maintenance contract, the time required for maintenance has to be schedule separately. In our organization we call these days “issue days”.


Figure 3: maintenance work takes some more hours away

If you’re lucky (given the current financial crisis) you will have customers asking you to do some new work that doesn’t fit into regular maintenance work. Of course, you already know you should try and do only one project at a time. So you tell those customers to wait until project A is finished. However, if the amount of work is small, your customer will find it very hard to swallow that he has to wait another three months for project A to finish. “It’s only 3 days of work! Why do I have to wait for 3 months? Surely you can squeeze this in between?” That’s why we decided to introduce “RfC weeks”, where an RfC stands for a Request for Change. It is one week per month reserved for relatively small jobs on existing products, whatever work that turns out to be. (And if no small jobs turn up, we just continue working on project A.)


Figure 4: one week reserved for tiny projects

Is that everything that you need to think of? Hell, no! What about your own personal development? When will you have time to experiment with new technologies? When will you have time to read a book, or the complete archive of your favorite blog (NOOP.NL)? If your organization is serious about your personal development, you will be allowed some time to read, experiment, and learn. In our organization we call these our “academy days”, and they need to be scheduled separately.


Figure 5: one day of personal development per month

That was all, right? Well, maybe. Maybe not. It depends on any other responsibilities still left unattended. Are you required to coach some junior software developers? Are you expected to attend several meetings per week? Are you involved in job interviews, or fixed price estimations? Do you do consultancy work for new customers? Do you prepare technical architectures for new projects? You will have to account for those activities as well.


Figure 6: various activities of one hour per day on average

As you can see in the last picture, the actual time you have available to work on project A has shrunk to almost one third of the month. Sure, your own situation may not be as extreme as in this example, and the exact numbers of hours will vary per person, but I would advise you to do the sums yourself. And don’t do this scheduling in your head! At the start of the month, when you plan your work for project A, you have to know how much time you have available. If you’re only doing a quick mental assessment of your responsibilities, you will always end up overpromising what you can do for project A.


(If you’re lucky, and your organization understands the importance of resource scheduling, you will have a resource manager or project manager doing all this work for you. Still, you might want to check if she has thought of everything. In dynamic organizations (like mine), where hundreds of customers and projects are battling over the availability of human resources, keeping track of people’s multiple responsibilities can be very hard. But if you apply some discipline to your schedule, you should be able to handle the most common resource allocation problems.)

Balancing work for multiple customers is a tough problem. You will have optimal results by optimizing resource allocation in such a way that all customers are just a little bit happy. And it is true that you should minimize the amount of task-switching between projects. If you can consolidate all maintenance work in one week per month, instead of one day per week, then do it! Likewise, aftercare in 2,5 days of 8 hours would be much better than 10 days of 2 hours. I’m sure you get the picture.

But whatever you do, it doesn’t change the amount of time that remains for customer A, which could be a lot less than you thought. It’s best the customer knows that before you start, don’t you think?

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  • Paul Marculescu

    It’s a good thing to try to sketch a monthly schedule as you did. It gives you a more realistic overview, otherwise you’re tempted to think you have all the time in the world for each of the projects.
    Also, besides letting the customer know how much you’re going to work on the project, I think it’s useful to let her know when. The customer would probably want to contact you quite often, and not specifying when this would be appropriate, you’d probably end up taking time from working on project B to communicate with customer from A.
    In this regard, I would make a small change in the “extreme” schedule you presented, by moving the hours for project B in such way, that they fit into full days as much as possible. So instead of having project B spread over 10 days with 2h in each day, I would put B in 2 full days + another half from a day split with Personal development. This minimizes the context switching from different projects and in my opinion context switching is bad for the schedule. 🙂

  • Jurgen Appelo

    @Paul: I agree with putting all work for project B together, if possible. (I also indicated as such in the article.)
    However, we often experience that we don’t know in advance *which* days need to be spent on project B. Because the rework for B depends on when the customer has finished evaluating the product and delivers the last couple of issues. (They often take quite a long time to do that.) So in the planning we usually spread these hours over multiple days, though in practice most of them are used all on the same days.

  • Pawel Brodzinski

    You can get some insight analyzing past schedules (and the way you’ve ovverrun them) and carefully accounting each hour of your work (for yourself, not for your managers so be exact).
    Some time ago I did a little exercise couting how much of our schedule goes to unproductive events or non-core tasks. It appears if you do the real work 8 hours a day you have to come back home really late.

  • Jurgen Appelo

    @Pawel: True. We try to plan our scheduled capacity per project/activity based on our experience. Still very hard though, because it can fluctuate a lot.

  • Eric Rodriguez

    Interesting approach to define how many time you “really” have on each project. But I’m also a bit concerned about the “planning” part. This doesn’t sounds to me as a “solution” but rather as an “analysis” of your every-day work.
    For me, I keep relying on a ratio of 3… you always take 3x more time to do something than the estimate (at least when you’re junior and make hyper-optimistic estimates)
    Anyway, you seem to have the same ratio: projA 160 -> 57 hours 😀
    Another approach could be using a rate limit for project. You only go from a total hours dedicated to each project to a maximum daily rate of hours available for each project. This way you can reschedule easily.
    Of course, avoiding multi tasking would be better 😉
    Thanks for your interesting post !

  • John Hunter

    Great post. I really do find that this type of thought is very helpful. Often the time needed for the “other stuff” is way under-estimated.

  • Ruby Chelmsford

    Hmm, you can say that it’s a common problem that would be encountered by first-time entrepreneurs. It’s quite a learning curve to learn how to attend many customers when time is limited. Patience can be in short supply for some people too, so it’s important to learn how to organize your schedule so you can handle and satisfy multiple customers.

  • Sonia Roody

    Dealing with multiple customers is definitely tough, especially for those new in the business. Customers, being the heart of any business empire, should always be number one in the priority list. True, it would be much more effective to set a time table to accommodate customers with various concerns.

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