Sources of change in a software project


Change is an integral part of the software development process. It’s what makes software soft. In fact, change is so important in software that it get’s it’s very own line in the agile manifesto

    Responding to change over following a plan

It’s been a long time since software teams believed in the unchanging quality of requirements documents, but we are yet to fully understand where change comes from and how it affects us.

It costs far much more to make core changes during development than it does at requirements. Boehm and Papaccio estimate it at 50 – 100 times more. Even with the advent of agile techniques, it is still worth it to control change as much as possible.

In this entry we shall be exploring the various sources of changes, this should hopefully help you anticipate and identify impending changes as soon as possible.

Change from the customers

Of all the sources of change, this is the one worth most consideration. The reason is that as a consultancy or even engineering department, you want to harness change as a competitive tool for your client.

No matter how well you run your requirements gathering sessions, there are requirements you are bound to miss. This is because knowledge builds on knowledge ideas on ideas.

To illustrate this point, think of a car. The first car was a very basic box with wheels that happened to move. But from this idea, people began asking questions such as:

  • Why can’t the seats be more comfortable?
  • Why do I have to be hot in the car?
  • Why do I have to manually change gears?

Today, these previously extraneous features are deal breakers.

In the same way, once development has started, your customers are guaranteed to have new ideas as they see your progress.

In this kind of situation, you want to carefully weigh your options. You don’t want to do exactly what the customer wants you may end up always chasing after the new shiny thing. You also don’t want to completely ignore their wishes under the guise that you know best.

Change from sales and marketing

This part particularly affects product companies.

The product owner declares this Big Hairy Audacious Goal

    We will build a one stop best in class application within the next 6 months

This is a great goal and everyone is excited about it. The engineers get to work “banging” it out. Somewhere within the development window, the competitor does a release that you had not even thought about. The sales team also wants to be able to sell the new feature so they insist that is also put in the product after all our product is best in class right?

It is tempting to think of your application as a big checklist of features, this is dangerous because then you will be locked in competition with other firms to produce more and more.

Kelly Walters makes a compelling argument in Agile Principle 8: Enough Is Enough! that you likely don’t need to develop 80% of the features.

Perhaps then the product owner should have come up with a better goal say

    We will build a product in the next 6 months that will improve our customers margins by atleast 10%

Change from developers

Developers, my favourite group!

More than any other stakeholder, developers have the highest intellectual and emotional investment in the project. They are the ones who had to deal with the design flaws, unexplainable bugs and late night coding.

Yet to them, requirements are usually provided as a checklist. In this case am also looking at a list of user stories as a checklist. Without an organising theme, developers will do what they do best, write the best-designed code that they can conceive off.

The problem here is that the devil is in the details. Your DBA may end up writing code that shortens query time from 10ms to 1ms. This is great, except for the fact that no one really specified that they have that requirement. Another example would be where your front end engineer goes out of their way to guarantee that the settings page will work for all screen sizes.

I believe by actively watching out for this sources of change, you will be in a better position to manage them when the changes do come.

What are the sources of change in your own projects? Talk to me in the comment section below or on my twitter @ jchex


Hidden Tension Between Sales and Development

Our boss once said:

 “There are people whose superpower is getting the signature on the dotted line”.

This may seem fairly obvious to other people, but to me, it was not. After all, a sale is an agreement to deliver a service (we are in the consultancy business) wouldn’t the people best placed to make the sale be the people who will do the actual delivering?

Well, I was wrong, as it turns out sales is an entirely different process from development. Sales tend to be more aggressive and charging while the development is more gentle and steady. These two forces complement each other, except when they don’t.

In this entry, I will be exploring some causes of conflict between the two teams and how they can be resolved for a stronger overall team.

Commitment to deadlines

Sales tend to be the first contact with the client. In some cases the client’s deadline is not arbitrary, something in their business environments such as trade show, shopping season or investor pitch is coming up. As the sales person, it is in your best interest to promise the client that whatever they need to be done will be done by that date.

The engineering team, on the other hand, has another belief set concerning deadlines, specifically:

    You can manage to deadline and let scope vary or manage to scope and let deadline vary.

This means that the engineering people can either work on a stripped down version of the product before the deadline or make no hard commitments but get it all done.

The problem then comes when the development team is given an engagement that just can’t be delivered within an already committed timeline.

To resolve this issue, the sales team should never give a time commitment. I mean this in the strictest sense, not a date on the calendar, not a range of days not even a ballpark figure without first consulting the development team!

Handling of issues

Let me let you in on a little secret, the dream of building a product from solid success to solid success is a beautiful one but only a fantasy. Nothing can save you from missteps in any non-trivial development.

To the sales team, problems are there to be solved. After all, we promised we will get this thing done and by God, we will!

The development team on the other hand does not like playing catch up, rather they would prefer to have a new planning session where commitments are renegotiated.

My take is that during times of great political risks, candour is a vital behaviour that maximises your chance of a positive outcome. After all, maybe, just maybe what you think is a big issue may turn out to be trivial to the client. Or it may be so important that they chose to have your work exclusively on that issue. Either way you have allowed them to exercise their proper role as custodians of priority of their product.

Unexpected “Aha”

During the normal course of development, the team may land on a great idea that would make the product 10X better. Of course, the same idea would also have the same impact on a competitor’s product.

If this is not a perfect opportunity for up-selling, I don’t know what is.

Perhaps because engineers are not typically compensated on basis of sales per quarter, they tend to see things in a different way. You see, human knowledge is never contained in one person. It grows from the relationships we create between each other and the world, and still, it is never complete.

Then to the engineers, this new knowledge seems like a gift to be given to the client team.

I believe the aim of any good engineering team should not just be to deliver to spec but also to delight the client with a beautiful product. Yet in the same vein, no development work should ever be done without explicit approval by the client. What may seem brilliant to you maybe garbage to someone else.

I will sue you

Whenever someone blurts out the words “I will sue them, you wait and see” I immediately get the impression that they have no idea how arduous the legal process actually is.

When serious issues arise in the project such as the client trying to poach the development team, the immediate reaction may be to channel all the energy used to win the client to now battering them.

Engineering culture, on the other hand, carries with it a different tone:

    Customer collaboration over contract negotiation

Yes, the client signed a contract, yes it seems like they are now trying to screw us over, no we will not aggravate the situation.

I believe that any contract is undersigned by a genuine human relationship, furthermore, this relationship is worth more than any piece of paper. Barring cases of outright hostility, all measures should be taken to preserve the relationship.

Have you ever experienced any tensions between your developers and your sales team? Talk to me in the comment section below or on my twitter @jchex


What is in an estimate?


It is easy to think of an estimate as one figure. Intuitively, it would seem that a feature such as a user management dashboard should take 5 days to build.

When we ask for an estimate from a developer, then what we expect is this single number.

Yet this single number can be quite misleading as we talked about in Why you should never give off the cuff estimates

You see the number of days it will take to complete any feature is not some kind of physical truth, rather it’s a derived quantity.

In this entry, we shall be looking at how the variables that determine the final delivery date interact with each other.

A trip home

I live and work in Nairobi, once every while, I travel to my hometown in Kisii county. Suppose I called home and told them am coming, the very first question they would ask would be

    What time do you expect to arrive?

This question is a simplified version of a client asking a developer, When can I expect feature X?.

Based on my experience travelling home, I probably would be able to give my family a solid estimate fairly quickly. But let’s suppose I did not know much about the trip, then how would I go about coming with an estimate?

How many Kilometres are there between Nairobi and Kisii? (Size)

This is the most important variable and the only one that exists independent of my activities. The distance between Nairobi where I am and Kisii where I want to be is representative of the work that needs to be done.

It is highly likely I would be able to agree with other people on the distance if nothing else.

If our estimate of the distance was to vary, then we probably don’t have a shared understanding of where we are trying to go. Eg if I estimated the distance to be 500km and my brother estimated it at 800km we are probably talking about different destinations or thinking of different roads.

In software, story points are used to indicate the size of the feature. Estimates of story points from different team members tend to cluster around the same value. In case there is a lot of variation, a discussion should ensue. It is probable that there is some misalignment in what the feature is about.

What are my means of transport? (Velocity)

When it comes to speed, means of transport is the most important factor. Will I, for example, be walking, driving or taking a flight. The different means have speeds that once more cluster. For example, walking can be done at 5km/hr driving at 100km/hr and a flight at 800km/hr.

Velocity is likely to vary even for the same classes of transport.

In software teams, velocity is measured via either story points/sprint or features/week. I personally prefer the first measure. While you can estimate this value, the most accurate values would come from looking at how you have performed historically. That is, what is the average velocity you have experienced over the last say three sprints.

The velocity is determined primarily by the skill level of the team followed by the morale and number of team members. In engineering folklore, it is said that the best engineers are 10X as productive as average engineers. Whether this is literally true or not, from experience, I know that progress is much faster with a senior team.

In an ideal situation, how many hours will it take me? (Duration)

The road to Kisii is full of perils. From a couple of black spots, flash flood areas, escarpments and corrupt public officials, there is a lot that can delay your trip. Even with none of this dangers, something as simple as having lunch is likely to increase the time it takes to get home.

So when we think about the ideal situation, we must think of the sunniest day where everything is clear and you maintain a constant speed from Nairobi to Kisii.

To derive duration we can, therefore, employ some basic math:

    duration = distance/speed

By using this computation, we can then arrive at the ideal time it will take to arrive.

Similarly, in software, we can calculate the number of story points or features we will deliver in that time period.

    time to delivery  = story points to deliver / velocity
    weeks to deliver features = no of features / features  per week

In practice how long will it take me? (Calendar time)

In real life, you have to eat lunch. Our task at this time is to determine how much time we will take considering the vagaries of life.

Suppose from previous trips, I know that I usually face some delays such as:

  • Jam at the escarpment (1h)
  • Slow traffic at flood plains (0.5h)
  • Lunch (0.5h)

Once I have arrived at my ideal duration, I would then need to add these hours to it to arrive at the calendar time.

    estimated calendar time = ideal time + expected delays

Similarly, in software, there are a lot of factors that affect feature development that is not part of development. In the entry When to ignore historical velocity we talk a bit about such factors.

So then for the software team, once you have arrived at your ideal duration, you can now add in external factors to the estimate to come up with the calendar time. This value is what the client and other stakeholders will likely be interested in. To ensure the estimates are dependable, consider some of this tips

Do you decompose your estimates and in what way? Talk to me in the comment section below or on my twitter @ jchex