Most important consideration in design

Replies

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  Manish Goyal

  "From view point of computer engineer"
  
  The major problem in design is pressure of time limit on developer or designer to complete a certain project within definite time limit,because of this pressure they don't pay attention to security which in turn results into security holes and a headache for client as well as company
  
  Few days ago i found a website of a university where one can easily login as a dean of university by using simple sql injection .Today there are solutions for sql injections but still people leave such vulnerabilities.
  
  we are running fast to compete with time, not with quality
• 

  Voltaire

  Thanks Goyal
  
  If I understand you correctly then your concern is safety. In my opinion, that is the right answer.
  
  As you know, a project e.g. a software project, consists of three 'legs': resources, time, scope. These three are arranged in a triangle such that all the ends meet. The area of the triangle represents the sum-total of all of these and may be expressed in monetary value. The inter-relation is that resources (material, manpower etc.) costs money. The longer those resources are required (time) the more it costs and thirdly; the bigger the scope is i.e. the more stuff that needs to get done the more resources are required and the more it costs. Companies generally try to control cost, as it is put. This means that they will typically increase the scope without increasing the necessary resources to meet the time requirement. In order to do this anyway they either demand higher productivity or longer hours or they produce an inferior item that still meets the outward appearance of functionality but does not meet all the customer's requirements in terms of quality.
  
  In y experience, inexperienced project managers are prone to make this mistake more readily than others. The scope has to be assessed from the outset and the delivery time must be realistic. Managers whose bonuses depends on appearances (control, efficiency etc.) often make promises they cannot keep and end up asking the impossible. There is an old saying - don't know if you've seen it:
  We the willing
  Controlled by the unknowing
  Are doing the impossible for the ungrateful
  We have done so much for so long with so little that we can now do anything with nothing
  
  And another:
  The impossible we do at once; miracles take a bit longer
  
  😉 Peace
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  Kaustubh Katdare

  Thread moved to CE Labs section.
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  durga ch

  I Believe the most important consideration in design - meeting the goal of the project. and second being - attaining the level of simplicity where - all the factors such as backward compatibility , easy understanding and scope for improvement and any changes in future can be accommodated, along side not compromising on security.
  For example - I am in process of developing a protocol for Layer 4 of OSI. Thinking what's the basic functionality of layer 4 of OSI my basic design should be able to not only fulfill all the existing L4 functionality but also be compatible for already established protocols like TCP as many older applications still run on TCP.
  Addendum: As has already been pointed out, defining a scope is important too.
• 

  Voltaire

  @Durga
  I would say then that the scope definition is of utmost importance for it is the scope that describes the goal or objective. Has it ever happened to you that the customer changes the scope later in the project? Let's say he wanted a program that rings a gold bell and then he finds that the gold bell is too expensive so he then changes the scope to a program activating a buzzer. Sometimes, what the client perceives to be, a small change can generate a heck of a lot of extra work.
  If this has happened to you, how did you manage it?
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  durga ch

  That is when we have initial agreement as a contract right? unless an until a scope is defined why would we proceed for a design? and when the project moves to design phase - as far as I know- any VERY important scope changes would cost money and time and they will have to be conveyed to the client. It then becomes necessary that we let him know - the quality might as well get affected. if the changes are not so very urgent they can always be as an enhancement.
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  Voltaire

  Sometimes clients change their minds. It is a project manager's nightmare. If this has not happened to you then you should by a big present for your negotiators and contracts people. 😀
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  durga ch

  I am not a project manager , but sometimes do help in defining scope, hence I do understand what a night mare it would be when I go up to a developer and say " we did not think our solution would end up looking like this - so can you change?" and we did have responses like " it will cost us 1 week time and 8000$ cost ".
  if we take it this way - we define scope- Solution designer does the design and developer ends up developing.
  But what if we missed out on scope and solution designer doesn't take up that dependency when he designs? it won't work- the whole solution breaks down right? In such cases - we will have to change the scope to include the left outs and complete the design.
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  Saandeep Sreerambatla

  Defining scope is very important!
  Since, In a recent project of ours we were actually developing a client facing report!!
  The design was given and people started working on it! estimations, test requirements all are set!
  At once, our client mind changed he needs the report in another way , it took good 2 months to change the design and develop a new one!
  We are lucky that we got enough time to complete , if not we would have faced many problems!
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  CIVILPRINCESS

  i can answer this question in the view of construction projects.
  
  if the strata is hard, then we can give shallower foundations. but if the strata is not hard and has a hard strata at great depths, then we have to design deeper foundations like pile foundation till it reaches the hard strata. so the strata details and the design of foundation accordingly is one important consideration. for example the incident of a over turning of a building in shanghai, china can be stated as example. for a apartment complex the had pile foundation. it was a clayey soil. when a pit was excavated near it for building a multi level car parking, the foundation could not take the pressure of soil in one side alone an the building toppled. this cannot happen. so the foundation is the most important design consideration for the construction projects.
  
  the other important consideration is the seismic zone it lies in. if the construction lies in the region of high seismic zone then we need to take this into consideration while designing. for this we'll be providing shear walls. we have seen many earthquakes in the past. take the Haiti earthquake for instance. hardly any building was able to fully resist the effect of the seismic forces. "it's not the earthquake that kills people... it is badly built houses that do kill". the most deaths occurred only when the buildings collapsed on the people. in this earthquake disaster nearly 90% buildings were destroyed. all the hospitals , art centers, public buildings were destroyed and the debris were blocking the roads which made it tougher to continue the rescue mission. the seismic design of structures allow these buildings to bear the forces up to a good limit.
  
  these are only some of the deign consideration as far as construction projects are concerned. i've put forth the examples from the past as i'm still a student and i've not yet faced any problems in the field.
  
  thanks
  -CP
• 

  Voltaire

  Excellent answer!
  You started with the geology way down below the surface, worked to the sub-surface and the included the seismology of the region. This is usually known, as you said, from events in history and measurement. You then moved to the foundation, walls and the roof - nice logical progression.
  Great to see your concern with safety. Well done!
  
  Has anyone noticed how the different disciplines seem to have a slightly different angle?
• 

  Voltaire

  The design was given and people started working on it! estimations, test requirements all are set!
  At once, our client mind changed he needs the report in another way ,

  For project managers this is a major challenge. Research indicates that changing the scope late in the project escalates the cost of that part eleven fold i.e. if it would have cost $10 it will now cost $110.
  Good post
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  limestone7000

  I have studied "Control System" last semester, in the reference of which i believe that for ANY system to be implemented, we should first check its STABILITY!
  we can do it various ways, like plotting the root-locus, or bode plots of the system!
  or we can prepare a mathematical model[equation] of that system and with the help of R-H criterion, we can find out whether the system is going to be stable or not,😒
  
  Without these legitimate methods, one should nvr implement a system!!😁
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  Voltaire

  Hi Limestone
  Indeed! Stable control is very important. Research has shown that stability in control makes more efficient processes and increases production. Go to your nearest production facility and ask the senior operators (the guys who control production from the DCS) and ask them what are the most import considerations in control. Some of them will tell you that simplicity and stability are the two most important ones. There is nothing worse than having to contend with a wayward control loop in the midst of a crisis. It has happened to me and it is not only strenuous but also dangerous because it detracts one's attention and uses up time that could be better spent on other, more important issues.
  
  When designing a control loop is very important to get the buy in from operations. They are the ones who will ultimately have to use it and I have seen situations where the control loop was less efficient but because they had asked for that design they gave the project the thumbs up because they are too proud to acknowledge defeat. In that case you can then propose a modification (the way you wanted to do it in the first place), give them credit for being so brilliant and do it your way anyway 😀
  
  Good post and keep it up!
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  shreyasm89

  The most important consideration in design is optimisation. While undertaking any project we often are faced with a situation where we have to choose between added functionality & cost constraints.From the technical point of view between output correction & complexity of the circuit. We may have numerous ideas in our mind for our design but it could happen that in pursuit of excellence we may have to compromise on the prime function of the circuit. Also added features in a design need more time to be incorporated. So my opinion is OPTIMISE.
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  CIVILPRINCESS

  yeah optimization is one important aspect too.
  
  the economicity and the use of project can be weighed too. for example if we build a dam for the purpose of irrigation to a large area we can also design it in the location where it can be used for other purposes too. like for hydroelectric power and such stuff. so it will be multi purpose and at the same time economical too.
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  Ramani Aswath

  CIVILPRINCESS

  the other important consideration is the seismic zone it lies in. if the construction lies in the region of high seismic zone then we need to take this into consideration while designing. for this we'll be providing shear walls. we have seen many earthquakes in the past. take the Haiti earthquake for instance. hardly any building was able to fully resist the effect of the seismic forces. "it's not the earthquake that kills people... it is badly built houses that do kill".
  -CP

  Here is a white paper that addresses some of these issues.
  #-Link-Snipped-#
  
  Bioramani