Currently our team of 11 people is working on a project on asp.net platform. Timeline for the project is of 8 months and we have already done 4 months. Now working on new functionalities we find that there are some flaws in the architecture of the system due to which we are facing lot of problems. Now whom to look-up for solving this ... the Team Lead or the Project Manager... Have you ever faced this scenario ? What is the best to do then..
If you've realised this and no one else has, and you want the project to succeed, then it's up to you to put a few extra hours in and figure out a plan, and then sell it to the people who are nominally responsible for the decision making.
Real projects do have "restarts". It doesn't mean that you throw away all your existing work. It means you find a new shell to fit pieces of that work into. This is a lot easier if your work-so-far consists of well-understood self-cohesive little components, loosely coupled with each other. This is why people work that way - because they know from experience that they're going to have to rearrange things. Almost all features added to programming languages over the decades are due to the fact that we know each chunk of code we write may be in for a choppy voyage - it may survive, but will probably have to cope with a lot of unfamiliar environments on the journey to release.
So you've noticed that relevant information emerges continuously, throughout a project. It doesn't conveniently all show up in a single burst right before you start typing code. Writing a specification document doesn't solve this problem at all. So you need to change the way you work so that the project draws in new information all the time - new emerging information from outside is the food that drives your project forward. Try to look forward to each new surprising revelation and greet it as a friend!
What does this mean? It means that the "architecture" parts of a project are no more stable than the "little details". You have to be able to change the architecture. You don't have enough information at the start to make a permanent decision about anything.
The underlying problem may be the fact that you have an eight month project in the first place. Real eight month projects (ones that succeed on time) are actually, if you look closely, a lot of shorter projects: 16 two week projects is ideal.
You need to put all the project's aims (so far) into a big list in priority order. Write each feature requirement from the user's perspective. "The user must be able to blah blah blah", that kind of thing. Avoid talking about the technical issues of the current design. Think about how a user would deal with having no product at all (or whatever they currently use) and talk about how their experience would be improved by a particular feature.
The important thing is the priority order. The aim is to be able to say: we only have time to ship with the first 10 items done. That's better than 9 items, which in turn is better than 8, and so on. But even with 8 items it would be better than nothing, because each item is a feature that by itself would improve the user's experience.
The list is called the backlog.
If you compare your work so far with the backlog, you'll typically find that you've been working on low priority stuff, because you imagine you'll need it later. Try not to do that from now on. The low priority stuff is... low priority. What if some new higher priority requests emerge between now and ship date? They almost certainly will! Despite what some people will claim ("It will be totally useless without feature A!"), you could probably ship with neither feature A nor feature B. But if you had to pick one, you'd go with feature A. And you may well have to ship without feature B, due to lack of time. So don't jeopardise A for the sake of being "ready" for adding B later. Only prepare in advance if it costs you next-to-nothing - leave places where you can add things, make everything extensible, but not if it slows you down right now.
Then start working on a new version of the product (cannibalising the work done so far where it makes sense) that takes care of the first few items on the list - the bare minimum. Spend no more than a week on this. A week is 6.25% of your remaining time, so it's actually pretty expensive. But at the end of this you have a picture of what you're ready to ship so far. That is the only way to measure your progress from now on.
The rest of your project consists of:
Repeatedly cranking out new working versions of the product, each time adding a few more features from the priority list. Get a small community of users to work with each version and give direct feedback to your team. Aim to do a new version every couple of weeks.
Turning the user feedback into new "stories" to go "on the backlog". This of course involves prioritising them.
You do this over and over, in short iterations, until you run out of time (you probably have time to do six to eight iterations). At the end of each iteration you have something to ship that is "better" (has more high-priority features, incorporates more feedback) than what you had at the end of the previous iteration. This is progress.
Each end-of-iteration release has two purposes: to show progress and make the user community a bit happier, of course, but also to elicit more feedback, to find out new information. Every version is both a solution and a probe. This dual nature continues after the first public release. A public release is a deep space probe that you send out into the solar system to send back pictures of strange new worlds (in the form of exception stack traces).
The whole thing is scientific and rational. You make decisions about order of work based on order of priority. You get constant feedback based on a working version of your product, instead of having to guess the feedback you'd receive from an imaginary version of your product.
People will respond to this approach by saying that it will be horribly "inefficient". Efficiency is a relative term. Projects that don't work this way always end up working this way in the end. But "in the end" is very late. Usually there's a mad panic for an extra N months after the original deadline, where the project keeps producing repeated versions of the product that are all "nearly right" or "nearly done", in a crazy self-deluded parody of iterative development.
Fortunately, you can start thinking and working this way at any time. Better to start halfway to the original deadline than shortly after it.
Just put up your issues in the team meeting that involves both the team lead and the project manager. Put forward all your views frankly and effectively. This would in turn help the future of the project and give a new insight to the PM.
Further all the 11 team members too can discuss this among themselves and share one another views.. not just about the problem... but also about the possible solution. In the end share all the valid solutions to the TL and PM. This whole process would eventually help to recover the project from this mid-development issues.
A good link for what to do is this
Raise the matter to your project manager. Present a list of options with as best an estimate as possible for time to complete each with an objective list of pros and cons.
Offer your advice as best you can, but at the end of the day it's probably not your call to make on which way it will be resolved.
For what you say it seems you have a Technical Debt.
That's a problem that every project faces, mainly because now yo have much more knowledge of the domain than 4 months before.
It's a tradeoff, if the changes are not very brutal you might pull them off. If they are radical, you might reach the deadline with some of the features and then schedule time for refactoring.
Remember, as real debt it will keep growing interests until you pay it off.
Good luck!
I'd start by getting a consensus across the team of what the issues are, and how they might be resolved. Ask yourselves: What's the overall impact? Is it a complete roadblock? Are there ways around the issues without having to make major changes? It might not be too serious, and by discussing the issues you might be able to agree an quick resolution.
Related
Longform Question:
When running unit tests on objects(s) whose purpose it is to track various lengths of elapsed time, is there any way to speed up the process rather than having to sit through it? In essence, if there’s a unit test that would take sixty or more seconds to complete, is there a way to simulate that test in one or two seconds. I don’t want something that will cheat the test as I still want the same comparable, accurate results, just without the minute of waiting before I get them. I guess you could say I’m asking if anyone knows how to implement a form of time warp.
Background Info:
I’m currently working with an object that can count up or down, and then does an action when the desired time has elapsed. All of my tests pass, so I’m completely fine on that front. My problem is that the tests require various lengths of time to pass for the tests to be completely thorough. This isn’t a problem for short tests, say five seconds, but if I wish to test longer lengths of time, say sixty seconds or longer, I have to wait that long before I get my result.
I’m using longer lengths of time on some tests to see how accurate the timing is, and if I’ve made sure the logic is correct so rollover isn’t an issue. I’ve essentially found that, while a short duration of time is fine for the majority of the tests, there are a few that have to be longer.
I’ve been googling and regardless of what search terms I’ve used, I can’t seem to find an answer to a question such as this. The only ones that seem to pop up are "getting up to speed with unit tests" and others of that nature. I’m currently using the MSTestv2 framework that comes with VS2017 if that helps.
Any help is greatly appreciated!
Edit:
Thanks for the responses! I appreciate the info I've been given so far and it's nice to get a fresh perspective on how I could tackle the issue. If anyone else has anything they'd like to / want to add, I'm all ears!
In 1998, John Carmack wrote:
If you don't consider time an input value, think about it until you do -- it is an important concept
The basic idea here being that your logic is going to take time as an input, and your boundary is going to have an element that can integrate with the clock.
In C#, the result is probably going to look like ports and adapters; you have a port (interface) that describes how you want to interact with the clock, and an adapter (implementation) that implements the interface and reads times off of the clock that you will use in production.
In your unit tests, you replace the production adapter with an implementation that you control.
Key idea:
There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies
Your adapter implementation should be so simple (by design) that you can just look at it and evaluate its correctness. No logic, no data transformations, just the simplest thing that could possibly insulate you from the boundary.
Note that this might be a significant departure from your current design. That's OK, and part of the point of test driven design; the difficulties in testing are supposed to help you recognize the separable responsibilities in your code, and create the correct boundaries around them.
Cory Benfield's talk on building protocol libraries the right way describes this approach in the context of reading data from a socket; read data from IO, and just copy the bytes as is into a state machine that performs all of the logic.
So your "clock" might actually just be a stream/sequence of timestamp events, and your unit tests then document "given this sequence of timestamps, then that is the expected behavior of the functional core".
The slower tests, that actually interact with the real clock, are moved from the unit test suite to the integration suite. They still have value, and you still want them to pass, but you don't want the delays they produce to interrupt the development/refactoring workflow.
I work for a market research company in the online space. We have been spending all of our cycles for over a year and a half building the next big thing in this space with regards to profiling our respondents (over time) to better place them in available surveys . Something that one of our researcher's has asked us for many times (rightly so) is a tool that will prove the worth of this new profiling system and predict the outcome of tweaks to it's many algorithms and rules to show which version of a rule set has a better outcome.
The goal is to be able to take a sliver of our profiling system (a static slice of Q&A data for a given time - sex:male/female, drinks:coke/pepsi/mt.dew, income:etc.) and run user agents (artificially developed software robots or agents) through our profiling system to see what the interactive results would be. As the Q&A data would be the same, the user agents abilities to choose answers would be the same, and only the algorithms and rules behind how the profiler works would change - this theoretically would allow us to pre-determine the outcome of any changes to our system. This result would then allow us to proof changes before pushing the changes to our production system. The hope would be that we could more easily catch any errors before releasing to the wild. But this would also allow us to test changes to the logic to hunt for optimizations in the profiler.
My question: For someone like me (C#/.NET mostly) who has really only worked in the web application space, where do I look to get started in building user agents that are able to interact with an outside system such as my profiling system? I specifically need to know how to spin up 1000 (one thousand) agents and have them interact with my profiling system (over a given amount of time) by being able to answer the questions that are presented to them by the profiling system based on characteristics that are dynamically defined on the user agent at the time of initialization.
An example of this is that I need some black agents, some chinese agents, some male agents, some female agents, some old agents, some new agents, some religious agents, some that drink coke, etc. and all of them mixed together to most appropriately resemble the world. We already have the demographic break down of our population so we can easily spin up 10% black males, 60% white female stay at home mothers, and all the other representations of our population.
My first thoughts for creating a system like this was to use the power of my XBOX 360, and some well thought out agents that resemble a person from an object oriented world with some added characteristics to be able to intelligently answer some questions...and guess at others.
In speaking with my colleague, it was suggested that I use some of the artificial intelligence frameworks out there and a 1000 cpu graphics card (we have one already) to get some super wicked fast performance out of loads of user agents. Where each CPU is an agent...(something like this).
Is there anyone out there with experience in this sort of thing? Proofing problems with a fictitious model of the world?
You say "interact with an outside system" - what is the interface to this system, and how does a person use it? Is it over the web? If so, you're wasting your time thinking about GPU optimisations and the like since your performance bottleneck will be the network, even over a LAN. In such circumstances you may as well just run the agents sequentially. Even if you could effectively spawn 1000 agents simultaneously (perhaps across multiple machines), chances are high that you'll just cripple the target server in an accidental denial of service attack, so it's counterproductive. However if you have the ability to change that interface to allow direct interprocess communication, you could go back to considering the massive parallelism approach. But then 1000 is not a big number in computing terms. It's likely you'd spend more time making the algorithm run in parallel than you'd save by having it that way.
As for 'artificial intelligence frameworks', I don't think there is anything quite so vague that would help you. AI and intelligent agents is a massive field - the book Artificial Intelligence: A Modern Approach which is a standard introductory text on intelligent agents is over 1000 pages long and contains maybe 20 or 30 totally independent techniques, many of which could apply to your problem, many of which won't. If you can specify more clearly what tasks the agent has to perform, and which inputs it has on which to make those decisions, picking a decent technique becomes possible. In fact, it may turn out that your problem doesn't require AI at all, if you have a clear mapping between agent demographics and decision making - you just look up the answer to use from the table you made earlier. So it's important to work out what problem you're actually trying to solve first.
I would like to create a simulation of a factory floor, and I am looking for ideas on how to do this. My thoughts so far are:
• A factory is a made up of a bunch of processes, some of these processes are in series and some are in parallel. Each process would communicate with it's upstream and downstream and parallel neighbors to let them know of it’s through put
• Each process would it's own basic attributes like maximum throughput, cost of maintenance as a result of through put
Obviously I have not fully thought this out, but I was hoping somebody might be able to give me a few ideas or perhaps a link to an on line resource
update:
This project is only for my own entertainment, and perhaps learn a little bit alnong the way. I am not employed as a programmer, programming is just a hobby for me. I have decided to write it in C#.
Simulating an entire factory accurately is a big job.
Firstly you need to figure out: why are you making the simulation? Who is it for? What value will it give them? What parts of the simulation are interesting? How accurate does it need to be? What parts of the process don't need to be simulated accurately?
To figure out the answers to these questions, you will need to talk to whoever it is that wants the simulation written.
Once you have figured out what to simulate, then you need to figure out how to simulate it. You need some models and some parameters for those models. You can maybe get some actual figures from real production and try to derive models from the figures. The models could be a simple linear relationship between an input and an output, a more complex relationship, and perhaps even a stochastic (random) effect. If you don't have access to real data, then you'll have to make guesses in your model, but this will never be as good so try to get real data wherever possible.
You might also want to consider to probabilities of components breaking down, and what affect that might have. What about the workers going on strike? Unavailability of raw materials? Wear and tear on the machinery causing progressively lower output over time? Again you might not want to consider these details, it depends on what the customer wants.
If your simulation involves random events, you might want to run it many times and get an average outcome, for example using a Monte Carlo simulation.
To give a better answer, we need to know more about what you need to simulate and what you want to achieve.
Since your customer is yourself, you'll need to decide the answer to all of the questions that Mark Byers asked. However, I'll give you some suggestions and hopefully they'll give you a start.
Let's assume your factory takes a few different parts and assembles them into just one finished product. A flowchart of the assembly process might look like this:
Factory Flowchart http://img62.imageshack.us/img62/863/factoryflowchart.jpg
For the first diamond, where widgets A and B are assembled, assume it takes on average 30 seconds to complete this step. We'll assume the actual time it takes the two widgets to be assembled is distributed normally, with mean 30 s and variance 5 s. For the second diamond, assume it also takes on average 30 seconds, but most of the time it doesn't take nearly that long, and other times it takes a lot longer. This is well approximated by an exponential distribution, with 30 s as the rate parameter, often represented in equations by a lambda.
For the first process, compute the time to assemble widgets A and B as:
timeA = randn(mean, sqrt(variance)); // Assuming C# has a function for a normally
// distributed random number with mean and
// sigma as inputs
For the second process, compute the time to add widget C to the assembly as:
timeB = rand()/lambda; // Assuming C# has a function for a uniformly distributed
// random number
Now your total assembly time for each iGadget will be timeA + timeB + waitingTime. At each assembly point, store a queue of widgets waiting to be assembled. If the second assembly point is a bottleneck, it's queue will fill up. You can enforce a maximum size for its queue, and hold things further up stream when that max size is reached. If an item is in a queue, it's assembly time is increased by all of the iGadgets ahead of it in the assembly line. I'll leave it up to you to figure out how to code that up, and you can run lots of trials to see what the total assembly time will be, on average. What does the resultant distribution look like?
Ways to "spice this up":
Require 3 B widgets for every A widget. Play around with inventory. Replenish inventory at random intervals.
Add a quality assurance check (exponential distribution is good to use here), and reject some of the finished iGadgets. I suggest using a low rejection rate.
Try using different probability distributions than those I've suggested. See how they affect your simulation. Always try to figure out how the input parameters to the probability distributions would map into real world values.
You can do a lot with this simple simulation. The next step would be to generalize your code so that you can have an arbitrary number of widgets and assembly steps. This is not quite so easy. There is an entire field of applied math called operations research that is dedicated to this type of simulation and analysis.
What you're describing is a classical problem addressed by discrete event simulation. A variety of both general purpose and special purpose simulation languages have been developed to model these kinds of problems. While I wouldn't recommend programming anything from scratch for a "real" problem, it may be a good exercise to write your own code for a small queueing problem so you can understand event scheduling, random number generation, keeping track of calendars, etc. Once you've done that, a general purpose simulation language will do all that stuff for you so you can concentrate on the big picture.
A good reference is Law & Kelton. ARENA is a standard package. It is widely used and, IMHO, is very comprehensive for these kind of simulations. The ARENA book is also a decent book on simulation and it comes with the software that can be applied to small problems. To model bigger problems, you'll need to get a license. You should be able to download a trial version of ARENA here.
It maybe more then what you are looking for but visual components is a good industrial simulation tool.
To be clear I do not work for them nor does the company I work for currently use them, but we have looked at them.
Automod is the way to go.
http://www.appliedmaterials.com/products/automod_2.html
There is a lot to learn, and it won't be cheap.
ASI's Automod has been in the factory simulation business for about 30 years. It is now owned by Applied Materials. The big players who work with material handling in a warehouse use Automod because it is the proven leader.
What are some good conventions to follow if I want to make my application harder to crack?
As long as your entire application is client side, it's completely impossible to protect it from being cracked. The only way to protect an application from being cracked is to make it have to connect to a server to function (like an online game, for example).
And even then, I have seen some cracks that simulate a server and send a dummy confirmation to the program so it thinks it's talking to a real, legit server (in this case I'm talking about a "call home" verification strategy, not a game).
Also, keep in mind that where there is a will, there's a way. If someone wants your product badly, they will get it. And in the end you will implement protection that can cause complications for your honest customers and is just seen as a challenge to crackers.
Also, see this thread for a very thorough discussion on this topic.
A lot of the answers seem to miss the point that the question was how to make it harder, not how to make it impossible.
Obfuscation is the first critical step in that process. Anything further will be too easy to work out if the code is not Obfuscated.
After that, it does depend a bit on what you are trying to avoid. Installation without a license? The timed trial blowing up? Increased usage of the software (e.g. on more CPUs) without paying additional fees?
In today's world of virtual machines, the long term anti-cracking strategy has to involve some calling of home. The environment is just too easy to make pristine. That being said, some types of software are useless if you have to go back to a pristine state to use them. If that is your type of software, then there are rather obscure places to put things in the registry to track timed trials. And in general a license key scheme that is hard to forge.
One thing to be aware of though - don't get too fancy. Quite often the licensing scheme gets the least amount of QA, and hits serious problems in production where legitimate customers get locked out. Don't drive away real paying customers out of fear of copying by people would most likely wouldn't have paid you a dime anyway.
Book: Writing Secure Code 2
There are 3rd party tools to obfuscate your code. Visual Studio comes with one.
BUT, first, you should seriously think about why you'd bother. If your app is good enough and popular enough to desire being cracked, it will be, despite all of your efforts.
Here are some tips, not perfect but maybe could help:
update your software frequently
if your software connects to some server somewhere change the protocol now and then. you can even have a number of protocols and alternate between them depending on some algorithm
store part of your software on a server which downloads every time you run the software
when you start your program do a crc check of your dlls that you load i.e. have a list of crc's for approved dll's
have a service that overlooks your main application doing crc checks once in a while and monitoring your other dependent dll's/assemblies.
unfortunately the more you spend on copy protecting your software the less you have to spend on functionality, all about balance.
another approach is to sell your software cheap but to do frequent, cheap upgrades/updates, that way it will not profitable to crack.
The thing with .NET code is it is relatively easy to reverse engineer using tools like .NET Reflector. Obfuscation of code can help but it's still possible to work out.
If you want a fast solution (but of course, there's no promise that you won't be cracked - it's just some "protection"), you can search for some tools like Themida or Star Force. These are both famous protection shells.
It's impossible really. Just release a patch often then change the salt in your encryption. However if your software get's cracked be proud it must be really good :-)
this is almost like mission impossible, unless you have very few customers.
just consider - have you ever seen a version of Windows that is not cracked?
If you invent a way to protect it, someone can invent a way to crack it. Spend enought effort so that when people use it in an "illegal" way, they are aware of it. Most things beyond that risk being a waste of time ;o)
I've not be coding long so I'm not familiar with which technique is quickest so I was wondering if there was a way to do this in VS or with a 3rd party tool?
Thanks
Profilers are great for measuring.
But your question was "How can I determine where the slow parts of my code are?".
That is a different problem. It is diagnosis, not measurement.
I know this is not a popular view, but it's true.
It is like a business that is trying to cut costs.
One approach (top down) is to measure the overall finances, then break it down by categories and departments, and try to guess what could be eliminated. That is measurement.
Another approach (bottom up) is to walk in at random into an office, pick someone at random, and ask them what they are doing at that moment and (importantly) why, in detail.
Do this more than once.
That is what Harry Truman did at the outbreak of WW2, in the US defense industry, and immediately uncovered massive fraud and waste, by visiting several sites. That is diagnosis.
In code you can do this in a very simple way: "Pause" it and ask it why it is spending that particular cycle. Usually the call stack tells you why, in detail.
Do this more than once.
This is sampling. Some profilers sample the call stack. But then for some reason they insist on summarizing time spent in each function, inclusive and exclusive. That is like summarizing by department in business, inclusive and exclusive.
It loses the information you need, which is the fine-grain detail that tells if the cycles are necessary.
To answer your question:
Just pause your program several times, and capture the call stack each time. If your code is very slow, the wasteful function calls will be on nearly every stack. They will point with precision to the "slow parts of your code".
ADDED: RedGate ANTS is getting there. It can give you cost-by-line, and it is quite spiffy. So if you're in .NET, and can spare 3 figures, and don't mind waiting around to install & learn it, it can tell you much of what your Pause key can tell you, and be much more pretty about it.
Profiling.
RedGate has a product.
JetBrains has a product.
I've used ANTS Profiler and I can join the others with recommendation.
The price is NEGLIGIBLE when you compare it with the amount of dev hours it will save you.
I you're developer for a living, and your company won't buy it for you, either change the company or buy it for yourself.
For profiling large complex UI applications then you often need a set of tools and approaches. I'll outline the approach and tools I used recently on a project to improve the performance of a .Net 2.0 UI application.
First of all I interviewed users and worked through the use cases myself to come up with a list of target use cases that highlighted the systems worse performing areas. I.e. I didn't want to spend n man days optimising a feature that was hardly ever used but very slow. I would want to spend time, however, optimising a feature that was a little bit sluggish but invoked a 1000 times a day, etc.
Once the candidate use cases were identified I instrumented my code with my own light weight logging class (I used some high performance timers and a custom logging solution because a needed sub-millisecond accuracy). You might, however, be able to get away with log4net and time stamps. The reason I instrumented code is that it is sometimes easier to read your own logs rather than the profiler's output. I needed both for a variety of reasons (e.g. measuring .Net user control layouts is not always straightforward using the profiler).
I then ran my instrumented code with the ANTS profiler and profiled the use case. By combining the ANTS profile and my own log files I was very quickly able to discover problems with our application.
We also profiled the server as well as the UI and were able to work out breakdowns for time spent in the UI, time spent on the wire, time spent on the server etc.
Also worth noting is that 1 run isn't enough, and the 1st run is usually worth throwing away. Let me explain: PC load, network traffic, JIT compilation status etc can all affect the time a particular operation will take. A simple strategy is to measure an operation n times (say 5), throw away the slowest and fastest run, the analyse the remianing profiles.
Eqatec profiler is a cute small profiler that is free and easy to use. It probably won't come anywhere near the "wow" factor of Ants profiler in terms of features but it still is very cool IMO and worth a look.
Use a profiler. ANTS costs money but is very nice.
i just set breakpoints, visual will tell you how many ms between breakpoint has passed. so you can find it manually.
ANTS Profiler is very good.
If you don't want to pay, the newer VS verions come with a profiler, but to be honest it doesn't seem very good. ATI/AMD make a free profiler... but its not very user friendly (to me, I couldn't get any useful info out of it).
The advice I would give is to time function calls yourself with code. If they are fast and you do not have a high-precision timer or the calls vary in slowness for a number of reasons (e.g. every x calls building some kind of cache), try running each one x10000 times or something, then dividing the result accordingly. This may not be perfect for some sections of code, but if you are unable to find a good, free, 3rd party solution, its pretty much what's left unless you want to pay.
Yet another option is Intel's VTune.